Thank you for all of the comments. I'm going to organise a follow up interview when more information becomes available as the development and testing continues. Please comment with your questions for the TurbAero team and I'll ask them during the next interview.
Anyone else reminded of the old Chrysler turbine car engine that used a recuperator like this? It had these heat matricies that would rotate slowly to absorb the exhaust heat and move it mechanically over to the intake. It was important in that car they cool the exhaust some before letting it out so they didn't melt anyone. Turbine exhaust can be a little hot untreated.
Recuperators are common in land vehicle turbine engines (such as the Honeywell AGT1500 in the M1 Abrams tank) and higher-efficiency stationary turbine engines. They're generally too bulky and heavy to be desirable for aero applications. Cosworth (the racing and high-performance car engine company) is trying to sell their "CatGen" recuperated turbine... and it's big and expensive for its power output.
The problem with all that exhaust heat is NOT that it might melt things but that it is throwing away a tremendous amount of energy. It makes a gas turbine without a recuperator, especially a small one, extremely fuel inefficient (though very high power-to-weight ratio).
The issue with the Car Turbines is emissions, it's difficult reducing NOx, which depend on combustion temperature, a hotter flame means more NOx, that combine with water in the air to produce nitrous and nitric acids, the most powerful corrodent known. N-Acetyl-cysteine po, let's say 300 mg bid, could protect respiratory tract from oxydizing agents, even asthma attacks during lightning storms and emissions during anti-cyclonic weather. When in WWII they injected water to reduce combustion chamber temperatures, an increased wear resulted. In Diesel engines, a 2% Water emulsion in fuel provided many advantages, adding more water was not better. Blessings +
yes, Phillip, but they, as you explained, where not using a heat exchanger with the recuperator conducting the heat through a wall, necessary when the pressures are different . Here I guess the compressor pressure ratio is between 2½ and 4 and so, the turbines. We tried to do this on a T 62. There the power turbine was on the same shaft, here the powertubine runs at a different rpm. Which makes the starting much easier.
OK - those numbers sound extraordinarily attractive. About the same fuel flow at altitude as a comparable HP piston, unit price slightly lower than a comparable HP piston, TBO 1000 hours higher, using a fuel source that (unlike 100LL) is not becoming harder and harder to find, and less $$ per hour on fuel costs due to Avtur being cheaper. If these guys can deliver on those numbers, this engine will be a winner. I really hope they can.
From what I've seen, the cruise fuel flow is equivalent to what I get flying LOP with a TSIO 520, which is a 300HP engine. Which means you're getting 150hp at 12.5gph with the turbine vs 195hp at 13.5gph with the piston. Turbine max power: 200hp, piston max: 300hp. Plus the turbine costs ~30k more than the piston.
@@johnheifner5813 Considering the difference in user between piston and turbine engine, I don't consider that to be representative of the engines themselves. Turbine engines appear mostly on business and commercial class aircraft operated with large maintenance budgets. Pistons are typically operated by cost conscious individuals and flight schools, neither of which are likely to perform the same level of preventative maintenance as would be expected on the typical turbine user.
@@diveforknowledge even RC turbines perform with less failure than piston engines… when you spin all the bits the same direction it sure makes things easier mechanically.
I hope this makes it to market. Back in 2005 Innodyne teased a turbine in the 165-225 hp range to target the IO-360 market. 18 years later it is still just an idea.
If they can get the Specific Fuel Consumption (SFC) figure down below .6 lbs per horsepower per hour they'll be doing good, below .55 they'll be doing GREAT! Piston engines typically run .45 and a really fuel efficient engine runs .42.
Tom Keeble ,an enginèer at Australia's aeronautical research laboratory (ARL) did a recperated turbine design and presented a paper on it at the 1976 conference on light aircraft in Sydney - perhaps this engine oŵes something to that research , it is a long sought dream for a turbine for light aircraft and with oxygen or pressurization could really deliver Frank Whittle's dream for high altitude efficiency.
I understand the need to certify but the experimental market is perhaps the best place to start. Great pool of platforms to provide a proving ground for what works and what needs improvement. Just Remember, there would be no Aviation if it wasn’t for Experimental aviation.
It's an immense engineering challenge. It's an immense regulatory challenge. It's an immense liability challenge. And that's before you even get to the antiquated attitude a lot of pilots have about tech changes and aerospace. With all of that said... I can't help but be hopeful! 🤞
I suspect that if they get this to work, it will sell to drone /UAV manufacturers for Military purposes rather than sports pilots. The airline industry might take it on as a new APU and the electrical industry might take it on for industrial power generation. If you could use it for Experimental aircraft, running on home heating oil, you might get it into the price range of the ordinary pilot but it's probably for Cirrus owners only.
one important number I didn't catch , weight ? ,looks the part though , With the stol competition planes pushing 400 Hp ,a light weight turbine could have a ready home. Mike Patey with his draco [ may she fly forever !]. 600 hp turbine has probably fueled a hunger for Turbine power . Personally I would prefer a revival of the Revtec motor ,full torque at low rpm, perfect fit for propellers ,and almost 40% real efficiency .With a bit of the F1 lean burn the efficiency would increase further too .
Was my first thought too. I was told to increase power, increase air by cooling, increase mass/volume, so you could make a smaller engine with same power. If feels counter intuitive ....
@@wouteranthierens A turbine engine's power is limited in how much fuel can you inject without overheating, so they typically run very lean fuel mixtures. More air doesn't solve that. lowering the compression ratio would solve that, perhaps by bypassing hot gasses around the compessor turbine, and driving the compressor at lower pressure. Or using water injection system like the b52.
The power turbine driving the propeller is a heat engine. The more heat you can put through it the more power it makes. Using otherwise waste exhaust heat gives a “free” energy boost to the power turbine.
Yes, it is opposite to an intercooler in a way, but keep in mind that an intercooler removes heat _before_ the engine's compression stroke while the recuperator adds heat _after_ the engine's compressor - that's a huge functional difference.
So how do the numbers look as egt drops and the dump losses add up? I guess recuperating is a proven tech the question is to integrate the compressor design and turbine drop balance to the recuperation drop. It “feels” to me that unless there is movable / adjustable features the engine performance will pivot around a set point of altitude and inlet temperatures. Maybe they have a movable nozzle between turbine and regen stage? Or a regen bypass valve? A price point of $85000 seems challenging. A big plus is (I am guessing) is that it will be for experimental only so cert cost us modest? What is required ? Maybe containment testing only? Plus fire test?
I wonder if it would work to use ejector valves for mixing exhaust with fuel air mixes for a preheated system? Or using a three stage turbine that mixes hot exhaust before hitting the combustion chamber?
PBS has a 240HP turbo prop, remember Innodyne and the RR250 project at Mooney. why were these not a commercial success? Compare this designs with a big jet engine and look at the differences. Big engines have an axial flow design with multiple compressor stages. Small turbines have a radial compressor that is less efficient. Big engines have a complicated turbine blade cooling to be able to handle higher combustion temperatures. Small turbines do not have this. Thermodynamic efficiency (=Carnot efficiency) depends on the combustion temperature. The higher the better, so it is limited by available materials. A piston engine can accept much higher combustion temperatures because it is not a continuous process. I like turbines very much because of their coolness factor. They are very reliable and much lighter. But it will be a tough challenge to overcome the above drawbacks.
PBS BSFC is around 550g/kwh. This engine is still high at 350g/kwh. With modern piston engines around 225g/kwh, small turbines are still far behind, especially now that we have good electronic engine management.
While that may be true, TBO is still a common specification for gas turbine aviation engines. P&W, for instance, issues TBO for each PT6 engine variant (perhaps dependent on specific application) in service bulletins. The suspicious thing is having any TBO established for an engine for which even the first prototype has not been built yet; clearly this is a target, rather than a real specification.
A turboprop replacement would be great. But all we see at the moment are turboprops in the tiny RC model aeroplane size, then a big jump from 200hp. There's nothing in between to replace the Rotax 447 and larger in the LSA market. We're all stuck with piston engines in that category.
There have been many gas turbine engines with recuperators, and they are all similar in function. There are two physical designs: a conventional heat exchanger as used by TurbAero, and a rotating disk which passes alternately through turbine exhaust and compressor output. Rover's JET1 had no recuperators, their T3 apparently had a conventional heat exchanger for recuperation, and I haven't found details on the later version. The other turbine cars (such as those from Chrysler) tended to use the rotating recuperator.
@@brianb-p6586 I remember seeing a cut-away drawing of a car turbine with a rotating heat exchanger, something like lots of crinkly metal plates in a disc, and the air flowed axially. A bit like the comprex pressure wave supercharger, but different. I'm quite sure that it was a Rover, but not 100%.
I always understood gas turbines are inherently less fuel efficient than reciprocating ones because the peak pressure/temperature in a reciprocating engine can be much higher than in a turbine one precisely because that peak is only very momentary, unlike a turbine where the HP turbine inlet must operate at a constant temperature. Sure a recuperator will help by greatly cooling the exhaust (ie extract the residual energy from the turbine outlet) but surely this is basic thermodynamics. Large turbines offset this lower Carnot limit by getting closer to it than large reciprocating ones through lower pumping and friction losses, but this is unlikely to be so for small turbines. Of course Turbaero's engine should have other advantages over piston engines, including lower aerodynamic profile, greater power-to-weight ratio, smoothness and inherent reliability, but I am sceptical that you will beat an old fashioned piston engine's fuel economy.
Large gas turbine engines run such high pressure ratios and peak temperatures that their efficiency is comparable to the most efficient gasoline engines (although still lower than similarly large diesels), but small turbines don't even approach that. The Wikipedia page for Brake-specific Fuel Consumption has some good examples.
It's compressor section pumping losses that's the big one. So much of the turbine power is wasted through pumping losses that there's not much available for work in comparison to the fuel consumed. Piston engines for all their shortcomings are remarkably good. Turbines traditionally were good at high altitude because the higher you go the faster you go for the same indicated airspeed, meaning the time to destination is less so the fuel burn less. Also at high altitude the turbine cycle naturally compresses its own air, the compressor pumping losses are also lower. This all adds up to being efficient in certain commercial situations but until now not so much for non commercial ops.
Ken, you are correct that diesels and spark engines peak temperature yield greater efficiency than a turbocharger simple GT. As economics allows both pressure (multiple compressor stages) and temperature (via blade cooling) improve GT efficiency. In complex GTs, the max pressure ratio a question of thermodynamically diminishing returns, and the upper temperature boundary is nitrous oxides (~2100F) emissions. For the low hp turbocharger-simple GA market, we are stuck with ~ 3.5 pressure ratio and ~1300F. The 3.5 ratio is about where a single stage centrifugal compressor goes supersonic; and 1300F is material limitation. Heat recuperation is effective, but at the expense of weight. Low pressure ratio recuperative simple GTs have existed since the late 50’s (Rover, Chrysler, Ford, GM all experimented. Honeywell engine in Abrams tank is recuperated) Past decade has seen supersonic high pressure ratio centrifugal compressors with shock wave diffusers. Simple GTs with supersonic compressors are flying in helicopters (P&W and RR/Allison & perhaps others). Experiments ongoing with ceramic turbines to increase temperature, but no joy yet. Simple GT efficiency also suffers from RELATIVELY thicker boundary layers and RELATIVELY broader clearances. As to our Australian buddies; with them well but not sanguine as to success.
@@danbenson7587 I assume that your strange term "turbocharger simple GT" is intended to mean a gas turbine engine with a single-stage centrifugal compressor... that's not immediately apparent.
The Free wheeling turbines have their shortcomings and are very unforgiving when they fail. Plus one will have to get a turbine rating from somewhere (single turbine ratings are not so readily available fro the certified aircraft market like from a TBM 700-950.. ) So after getting a rating on a 500-850hp turbine, you really want to go back to a 200hp turbine? I'd think that development should have been pegged at the 350hp+ market. Now as for Fuel efficient, well that is usually at FL 220+ and cabin heat is sorta needed, plus a mask and an IFR rating.. Down low, you've got a fuel pig that will eat the extra weight of the piston engine in an hour.. What is needed is Liquid Piston to get their shit together and release a version of their engine in a 200hp (150Kwh) version with a turbo boost, or a doubled up 80Kwh combination (so you can loiter on one engine)...
@@abel4776 MOSAIC is being opened up for the used aircraft market s my impression.. more so for the Beechcraft V35's and such. to keep a sufficient interest in the pilot development market.. that is my impression (I'm a former owner).
$85k is the target price point! A brand new IO360 is about 40k with core exchange. Any mechanic can work on my Lyc. Non American companies are always pitching kerosene engines to us Americans, as if dudes who shell out 100k for that turbine care about the price of fuel.. Like, dude, just because it ain't available in your countries... Avgas is readily available in America.
As with any recuperator, the heat is added after the compressor. In any gas turbine, compression is followed by heating in the combustion chambers, then by expansion through the turbine. As shown first @1:25 and explained starting @2:16, the recuperator acts as a first stage of heating which doesn't consume fuel, so the effect is simply to reduce fuel consumption for the same power output... and thus greater efficiency. Heating the air _before_ the compressor would not work for either power output or efficiency.
@@jimosborn390 It doesn't make sense for a piston engine only because there is no practical way to transfer heat into the compressed air in the combustion chamber, especially in the zero available time after the compression stroke and before combustion.
@@brianb-p6586 jimosborn390 is correct. Piston engines heat up the air much higher than a turbine. this is done with the compression ratio. A piston engine has a much higher compression ratio but is limited by pre and post ignition. Piston engines work on pressure, turbine work on flow more or less.
The start process is going to have to be idiot proof though. Watching the now "liquid" pieces of your powerplant flowing out the exhaust would be a disturbing experience. I would like to have a fiddle with the Emulator they have for this turbine and see how fast the fuel tanks drain at "flight training" altitudes. Would also be interesting to see the numbers in the sub FL200s too. I hope it comes to fruition unlike the Italian ceramic turbine when I was flying a C205 in the early to mid 80s when climbing with a load of skydivers in ISA +20 temps was no fun. Added extra precious time to my logbook though.
It's not clean or efficient enough for automotive use. There have been many gas turbines designed and built for automotive use, almost all with recuperators, and all have failed due to inefficiency and operational issues. In a series hybrid configuration most of the operational issues would be resolved, but efficiency is still too low. With current requirements, turbines generally have excessive emissions, as well. There is nothing about this specific design which makes it suitable for automotive applications. That's not a criticism, as it is designed specifically for light general aviation aircraft... not cars and trucks.
Energy is extracted from the gas which results in pressure drop across the turbine. This rapid reduction in pressure results in temperature drop due to the Joule-Thomson coefficient/effect en.wikipedia.org/wiki/Joule%E2%80%93Thomson_effect
"There is no fuel-efficient turbine engine for this category of aircraft". Heron engines is flying a turbine in a Bristell and Turbotech has a running engine (with recuperator)?
I don't think there are any applications, especially in land based applications. Companies such as Wrightspeed (with their "Fulcrum" radial inflow, axial turbine, recuperated, 80 kW turbine engine and generator set) have developed similar engines, progressed far beyond TurbAero's current state, and failed to find commercially viable applications.
@@brianb-p6586 I can see this as a combined electric generator and heating system for a house, a small race car power plant, or an engine for a refrigerated truck.
@Chris Henniker combined heat and power systems can be effective, but 200 HP is way too big for a system for a house. It's also too big for a reefer unit. Racing class rules are very specific about engines; there are very few if any which allow gas turbines.
Comparing dollar for dollar, also take into account the fact that Jet fuel is cheaper than Avgas, about 20% on average. That brings the cost to operate a lot closer ;)
@Richard of Oz You sound like all the turbine people trying to make it sound better by comparing it to an engine from 1930. I'm talking about a modern engine that uses regular 98 petrol. Jet a1 is about 30% more expensive than 98. The turbine uses 40% more fuel at best, and this engine costs about minimum 3 times as much initially as a modern engine. Of all the engines and companies, none have made honest comparisons, they just say it's comparable.
@@maddogmorgan1 this engine is simple. A few rotating parts when compared to an ICE or even a transmission. The P-51 mustang was designed and built in 6-8 months…. So it can be done. They’re just treading water with an inept number of people working on the project.
@@RichardofOz Yep! But it took the RAAus decades to lift the stall and increase the weight because Carmody refused everything and the RAAus board were in his pocket, they done nothing to advance sport and recreational aviation. Experimental won't advance any further, GA is as good as dead. Fuel is too expensive, maintenance costs are through the roof, and no work ethics anymore. Hangerage is too expensive even if you can find it. Local government want their pound of flesh and refuse freehold tital. Holbrook made a start and it all died at Wentworth when the developers got too greedy.
Ultimately, we won't see the claimed efficiencies; any weight saved by the lighter engine will be eaten up by the jet fuel; you'll need more gallons, and each gallon is 15% more than avgas. My day job is at a company building the most efficient jet engines on the planet, and also the largest. It's not easy-a 5% gain is monumental.
Thankyou for building this. I have often wondered why the heat exchanger has not been used more often. May I ask one question? Could you put the heat exchanger between the two power turbine stages? This would be at a higher temperature and hence more efficiency but run colder air through the second power turbine. Lower flow rate but denser and colder.
Read up on the Achates 2 stroke engine..........Cummins diesel makes it for the US Military. 50 to 55% thermal efficiency........no valve train. Can run high compression on any fuel, from gasoline to diesel. Would completely murder a jet turbine on fuel efficiency.
Does anyone remember the ERCO ? (Google, Jessica Cox for ref...) A plane designed and built in the late 1930's that was last known as the A2 before the company changed hands (Again) to what we know as the Mooney This was the safest plane ever made and also the most fuel effient even when compared to modern setups . I wonder how this would go with a revisit, redesign and upgrade to Turbo Prop , with this much power available it could be a 4 seater that is Fast , Safe and extreamly practicle with that economy. And would look amazing with that classic Twin tail ...Maybe? Ok probably just me but I like the Twin Tail setup , it's like the spair tyre on a 4X4 it just goes there. This could save Cirrus from the out dated engine they have a sick fasination with too
It's amazing how most initial improvements to efficiency in torque converters, through P.R.T. on radials etc., are the number of the universe. In the human body, 20 minutes is the basic cycle and many other things. 20/20 perfect vision, lowest one can hear 20 hz, most 20khz (all on average in all for average adult). Average adult has about 20 square feet of skin...
All good…but these engine and aircraft “under development “ are always an unknown and most never become a reality and investors money is usually lost forever.
Sorry but at 12.5 gal/hour at cruise altitude, it is 25% more fuel burn than a conventional airplane engine. Sure it can produce more horsepower but lets hope the airplane is designed to fly at more than 250knotts
You are talking about your typical four-cylinder, 360 cubic inch piston engines which burn at roughly 10 gallons per hour. But, these produce only 180 horsepower. The only things coming anywhere close to 250 knots are powered by larger, six-cylinder, 540 and 550 cubic inch engines burning much more fuel. So, this may be a good compromise of lower lead emissions, lower maintenance time, lower per gallon costs, etc.
@@deanfowlkes There is no lead in the future because the FAA has approved at least one non-lead avgas. More are coming. I have no problem of experimenting with new propulsion system but to say this is the same as piston is stretching it. Turbine burns more fuel, period. Turbine is efficient at higher altitude based on the speed they can fly, and turbine aircraft are generally larger so they can carry more fuel. The smaller general aviation airplane are generally designed to carry about 40 gals of fuel and when they are leaned, they burn less than 10 gal/hour. Burning 12.5gal/hour is at least 25% or more than conventional avgas.
@@2Phast4Rocket - If you notice, I never disputed the claim of the turbine having a 25% greater fuel burn. I stated the trade off may be worth it. You absolutely can get a better than 10 gallon per hour fuel burn at cruise burning lean of peak at altitude. I used to fly an old C172M with a constant-speed STC that could really sip fuel (comparatively). Rotax powered aircraft can get in the 5-6 gallon per hour range at the expense of horsepower and useful load. As far as non-lead Avgas, that is on its way. Unfortunately, it is brand new. Even in an area that is serviced by a major Class B and several D, E, and G airports, there are none that have the new unleaded. It will be years and maybe decades before it is widely available. It may never be widely available worldwide. 100LL is becoming a scarcity outside of the US.
You guys do realize they wouldn’t burn avgas but could just burn Jet fuel, aka kerosene with freeze agents. The only advantage I could see of this is increased altitude if the cockpit is pressure rated. It can take advantage of the thinner air and higher air stream speeds and optimally cruise at a higher rate of speed. Thus the fuel consumes per hour would net you greater distance. So at the end of the day. It’s all about the airframe. If it can’t handle the speed and altitude requirements. Not worth it. Unless you want that turbo prop engine sound I guess. I mean it’s their own aircraft. If your willing to get Willy with your power plant, why not give it a shot if you got the moola.
@@egondro9157 - We do realize that piston-props burn Avgas or the new No-Lead and turboprops burn Jet A. That is where the debate lies. Is it worth it. Avgas costs more than Jet A. No-Lead will more than likely cost more than Avgas. I don’t know that for a fact since none of my local airports carry the No-Lead, yet. Factoring the cost of the fuel, the claimed fuel burn, and the claimed maintenance intervals, this engine may be a viable alternative.
The UL Power UL520iS used in the DarkAero design is smaller, lighter, and more efficient than the claimed dimensions and performance of the TurbAero TA200... for the same peak power. Since TurbAero only claims any advantage at high altitude and the DarkAero is unpressurized, the turbine would be unsuitable in every way except for vibration.
This is taken directly from the Chrysler turbine engine from the 1960's, and it's stupid. You're basically taking a 1000HP capable turbine and reducing the power output to 200HP by pre-heating the air. Just use a smaller turbine. If 200 HP is your goal, a large hobby jet engine will do the job.
No, that's not how it works. The air is not being preheated (before the compressor), the first stage of energy input is from waste exhaust heat rather than burning fuel.
@@brianb-p6586 re-read what you just wrote. The exhaust is pre-heating the intake air. Look up the "re-generator" from Chrysler. The hotter the air, the less molecules, the less fuel that is needed. Ie. You produce a lot less power for a little fuel savings. Chrysler claimed it was because you don't need to waste energy to heat to incoming air and therefore save on fuel. However you want to look at it, it's the same thing from the 60's. I would recommend just using a smaller turbine. Something the size of a large turbo could produce 200 hp and use less fuel.
@John Doe I know what I wrote, but you seem to not understand it or how a gas turbine functions. In a Brayton cycle (of which a gas turbine is the most common example) after the compressor heat is added in an isobaric section, followed by expansion in the turbine section. Thermodynamically, it doesn't matter if the heat is added by combustion of fuel or transfer through a heat exchanger, although pressure drop due to flow resistance in any part of the flow path is undesirable.
They haven't even built one prototype yet, so there's no cutaway. Renderings of the internals would be good, but I wouldn't expect internal dimensions from any manufacturer, especially of a product not yet in production.
RUclips recommended a video about another similar engine which appears to actually exist: the TP-R90 from Turbotech SAS of France (search for "turbotech-aero"). Their product page shows a cross section; the TurbAero engine is probably very similar.
It's fuel efficient FOR A TURBINE, but you're still getting less power for more fuel than you would with a piston. Could be a step in the right direction though, who knows what will happen in the long run?
@@diveforknowledge Gas turbines are INHERENTLY less efficient that reciprocating engines, because physics. Google "Carnot efficiency". That aint gonna change unless the Second Law of Themodynamics changes.
Um,,, even if they exceed their power goals and production costs… There is going to be some effort to keep them out of the market; by competitors, bureaucrats, and fuds who don’t like anything new. The flying car was invented and successfully flown in 1947…
He said $85,000. That is a dream price. It WILL be higher. Much higher. Probably at least double. Look at Icon A5......went from $129,000 to nearly $400,000.
If it were easy to recoup an additional 20% of useful work by installing a recuperator, with acceptable weight, complexity, cost and service life trade-offs - everybody would be doing it. In fact, OEMs would be jumping at 2%, let alone 20%. Yet, nobody is. I honestly wish these guys best of luck, but my skepticism is very strong.
While the efficiency improvement is plausible, I agree that other factors make it difficult to incorporate a recuperator. Recuperators are routinely used by established gas turbine engine manufacturers, but not in aeronautical applications... and not even in many stationary applications (where fuel is cheap).
I have just run across another new gas turbine engine manufacturer who is a few years ahead of TurbAero and is using a similar recuperated design: Turbotech SAS (of France, look for "turbotech-aero"). Their engine is at lower power (90 to 100 kW continuous, rather than 150 kW), and is targeted to replace Rotax installations. It has not been successful yet.
Small turbines have a low compression ratio so the air is not heated as much as larger turbine engines. The mass of air flowing through is also much lower so there is less air to heat up. With a large turbine that already has a high compression ratio it is not needed, plus it would restrict incoming air, plus the volume of air would require a very large recuperator.
I thought you were going to be flying by this time from previous comments last year. It looks like a mock up. I predict it will never fly. Allison Model 250, now Rolls-Royce M250 is the logical choice for small turboprop for a fixed wing plane (about 300-420 HP). Built a plane that can handle a PT6 (550 to 1600 HP), Garrett TPE331 (575 - 940HP).
@@DylanClements98 The dream of turbine. I have flown turboprops and jets professionally. Great for commercial, military and rich people, corporate jets and turboprops. For GA pilots, private owners, who are not wealthy, flies well 100 hours a year, a piston under 350 HP is great. You can buy used jets cheap but cost of fuel and maintenance everything else is astronomical. Fuel is not measured in MPG but Gallons Per Mile. (Jets use fuel in pounds but the point is... thirsty.) Their "economizer" is not a new idea. Their mock up has one in plastic 3D printed. The predicted power and fuel flow numbers out of thin air, wild guessing. Again the Allison Model 250, now Rolls-Royce M250 has been used in helicopters and a few fixed wings, including P210 and Beechcraft Bonanza turboprop conversions. They are OK but the airframe is speed limited and for the cost it does not do much more than a Continental IO550 turbocharged engine. Years ago you cold get Allison 250's out of APU Generators and convert them. You are far better buying an old TBM750 with a PT6 with some time on it (and pre purchased inspected to assure no cracks in combustor or other expensive issues). Before the pandemic you could get one for $0.75M and have a real plane that can do things. I know a Sonex Jet owner/pilot. The SubSonex as they call it uses a tiny drone jet. It has to be overhauled every 250 hours I recall. It is an oversized RC jet engine. It takes a long runway to get in air. Once up it scoots along but not for long, it has a range of only a few 100 miles, like the BD5J. Cool plane but a single seat toy, very cool toy but still. However if that is your dream go for it. However that turbine dream will not be powered by this TurbAero engine... nope. TurdAero. Ha ha.
The Allison/Rolls Royce engine tops out around 450hp and was designed as a helicopter engine. Runs out of guts over 12,000 feet or so. And costs in the $400,000 range. No way this engine will be $85,000.
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Thank you for all of the comments. I'm going to organise a follow up interview when more information becomes available as the development and testing continues. Please comment with your questions for the TurbAero team and I'll ask them during the next interview.
Anyone else reminded of the old Chrysler turbine car engine that used a recuperator like this? It had these heat matricies that would rotate slowly to absorb the exhaust heat and move it mechanically over to the intake. It was important in that car they cool the exhaust some before letting it out so they didn't melt anyone. Turbine exhaust can be a little hot untreated.
Recuperators are common in land vehicle turbine engines (such as the Honeywell AGT1500 in the M1 Abrams tank) and higher-efficiency stationary turbine engines. They're generally too bulky and heavy to be desirable for aero applications. Cosworth (the racing and high-performance car engine company) is trying to sell their "CatGen" recuperated turbine... and it's big and expensive for its power output.
The problem with all that exhaust heat is NOT that it might melt things but that it is throwing away a tremendous amount of energy. It makes a gas turbine without a recuperator, especially a small one, extremely fuel inefficient (though very high power-to-weight ratio).
The issue with the Car Turbines is emissions, it's difficult reducing NOx, which depend on combustion temperature, a hotter flame means more NOx, that combine with water in the air to produce nitrous and nitric acids, the most powerful corrodent known.
N-Acetyl-cysteine po, let's say 300 mg bid, could protect respiratory tract from oxydizing agents, even asthma attacks during lightning storms and emissions during anti-cyclonic weather.
When in WWII they injected water to reduce combustion chamber temperatures, an increased wear resulted.
In Diesel engines, a 2% Water emulsion in fuel provided many advantages, adding more water was not better.
Blessings +
yes, Phillip, but they, as you explained, where not using a heat exchanger with the recuperator conducting the heat through a wall, necessary when the pressures are different .
Here I guess the compressor pressure ratio is between 2½ and 4 and so, the turbines.
We tried to do this on a T 62.
There the power turbine was on the same shaft, here the powertubine runs at a different rpm. Which makes the starting much easier.
OK - those numbers sound extraordinarily attractive. About the same fuel flow at altitude as a comparable HP piston, unit price slightly lower than a comparable HP piston, TBO 1000 hours higher, using a fuel source that (unlike 100LL) is not becoming harder and harder to find, and less $$ per hour on fuel costs due to Avtur being cheaper. If these guys can deliver on those numbers, this engine will be a winner. I really hope they can.
I'm looking forward to seeing the prototype and real world figures, but yes it sounds very promising!
From what I've seen, the cruise fuel flow is equivalent to what I get flying LOP with a TSIO 520, which is a 300HP engine.
Which means you're getting 150hp at 12.5gph with the turbine vs 195hp at 13.5gph with the piston.
Turbine max power: 200hp, piston max: 300hp. Plus the turbine costs ~30k more than the piston.
@@diveforknowledge It's also a turbine which have a failure rate in the order of 1:375,000 hrs vs 1:4000 hrs for a piston engine.
@@johnheifner5813 Considering the difference in user between piston and turbine engine, I don't consider that to be representative of the engines themselves. Turbine engines appear mostly on business and commercial class aircraft operated with large maintenance budgets. Pistons are typically operated by cost conscious individuals and flight schools, neither of which are likely to perform the same level of preventative maintenance as would be expected on the typical turbine user.
@@diveforknowledge even RC turbines perform with less failure than piston engines… when you spin all the bits the same direction it sure makes things easier mechanically.
I hope this makes it to market. Back in 2005 Innodyne teased a turbine in the 165-225 hp range to target the IO-360 market. 18 years later it is still just an idea.
Best of luck to them. It's an ambitious project
fingers crossed this all works out!
that's straight up genius gearhead work.
If they can get the Specific Fuel Consumption (SFC) figure down below .6 lbs per horsepower per hour they'll be doing good, below .55 they'll be doing GREAT! Piston engines typically run .45 and a really fuel efficient engine runs .42.
research the Reynolds number
@@theairstig9164 There is no reynolds number used here bud...
Tom Keeble ,an enginèer at Australia's aeronautical research laboratory (ARL) did a recperated turbine design and presented a paper on it at the 1976 conference on light aircraft in Sydney - perhaps this engine oŵes something to that research , it is a long sought dream for a turbine for light aircraft and with oxygen or pressurization could really deliver Frank Whittle's dream for high altitude efficiency.
EASY answer for an airplane like a cirrus sr22. Type of customer and type of flying those airplanes do is perfect for a setup like this
Sounds awesome- very best wishes for a successful outcome.
I understand the need to certify but the experimental market is perhaps the best place to start. Great pool of platforms to provide a proving ground for what works and what needs improvement. Just Remember, there would be no Aviation if it wasn’t for Experimental aviation.
It's an immense engineering challenge. It's an immense regulatory challenge. It's an immense liability challenge. And that's before you even get to the antiquated attitude a lot of pilots have about tech changes and aerospace. With all of that said... I can't help but be hopeful! 🤞
If it was easy, everyone would be doing it. Awesome to watch the development of it over the years.
I suspect that if they get this to work, it will sell to drone /UAV manufacturers for Military purposes rather than sports pilots. The airline industry might take it on as a new APU and the electrical industry might take it on for industrial power generation. If you could use it for Experimental aircraft, running on home heating oil, you might get it into the price range of the ordinary pilot but it's probably for Cirrus owners only.
one important number I didn't catch , weight ? ,looks the part though , With the stol competition planes pushing 400 Hp ,a light weight turbine could have a ready home. Mike Patey with his draco [ may she fly forever !]. 600 hp turbine has probably fueled a hunger for Turbine power . Personally I would prefer a revival of the Revtec motor ,full torque at low rpm, perfect fit for propellers ,and almost 40% real efficiency .With a bit of the F1 lean burn the efficiency would increase further too .
drifts closer to adiabatic operation; the recuperator seems to work opposite to that of the turbocharger's intercooler.
Was my first thought too. I was told to increase power, increase air by cooling, increase mass/volume, so you could make a smaller engine with same power. If feels counter intuitive ....
@@wouteranthierens A turbine engine's power is limited in how much fuel can you inject without overheating, so they typically run very lean fuel mixtures. More air doesn't solve that. lowering the compression ratio would solve that, perhaps by bypassing hot gasses around the compessor turbine, and driving the compressor at lower pressure. Or using water injection system like the b52.
The power turbine driving the propeller is a heat engine. The more heat you can put through it the more power it makes. Using otherwise waste exhaust heat gives a “free” energy boost to the power turbine.
I initially thought the same thing having come from an automotive background
Yes, it is opposite to an intercooler in a way, but keep in mind that an intercooler removes heat _before_ the engine's compression stroke while the recuperator adds heat _after_ the engine's compressor - that's a huge functional difference.
I wonder whether it could also be used as an APU for a large airlinger.
How about a 100hp version?
Looking forward to the IO550 competitor!!! 😃
That’s what the Abrams tank uses in its turbine, and it works very well.
Google tells me it uses the Honeywell AGT1500
@@RichardofOz I think he means it uses recuperator tech.
That is 2000 hp range.
@@alexlo7708 1500 hp... but yes, the Abrams tank engine is much larger than TurbAero's proposed engine.
@@aowen2471 Yes, presumably that's what he meant, and the AGT1500 does have a recuperator.
So how do the numbers look as egt drops and the dump losses add up?
I guess recuperating is a proven tech the question is to integrate the compressor design and turbine drop balance to the recuperation drop. It “feels” to me that unless there is movable / adjustable features the engine performance will pivot around a set point of altitude and inlet temperatures. Maybe they have a movable nozzle between turbine and regen stage? Or a regen bypass valve?
A price point of $85000 seems challenging.
A big plus is (I am guessing) is that it will be for experimental only so cert cost us modest? What is required ? Maybe containment testing only? Plus fire test?
I wonder if it would work to use ejector valves for mixing exhaust with fuel air mixes for a preheated system? Or using a three stage turbine that mixes hot exhaust before hitting the combustion chamber?
PBS has a 240HP turbo prop, remember Innodyne and the RR250 project at Mooney. why were these not a commercial success?
Compare this designs with a big jet engine and look at the differences.
Big engines have an axial flow design with multiple compressor stages. Small turbines have a radial compressor that is less efficient.
Big engines have a complicated turbine blade cooling to be able to handle higher combustion temperatures. Small turbines do not have this.
Thermodynamic efficiency (=Carnot efficiency) depends on the combustion temperature. The higher the better, so it is limited by available materials. A piston engine can accept much higher combustion temperatures because it is not a continuous process. I like turbines very much because of their coolness factor. They are very reliable and much lighter. But it will be a tough challenge to overcome the above drawbacks.
It wasn't a success because it sucked three times as much fuel
PBS BSFC is around 550g/kwh. This engine is still high at 350g/kwh. With modern piston engines around 225g/kwh, small turbines are still far behind, especially now that we have good electronic engine management.
The Mooney / RR project got interrupted by a Great Recession…
The project announcement couldn’t have seen the financial disaster coming…
You should develop a high output generator for use in hybrid-electric VTOL craft.
$85,000 seems like a lot. How does that compare to the Piston alternatives?
What about torroidal prop
What about 100-150 HP range?
Quoting a 3,000 hour TBO sounds suspicious in that turbines’ rebuild requirements are typically governed by hot cycles, not tach time.
While that may be true, TBO is still a common specification for gas turbine aviation engines. P&W, for instance, issues TBO for each PT6 engine variant (perhaps dependent on specific application) in service bulletins. The suspicious thing is having any TBO established for an engine for which even the first prototype has not been built yet; clearly this is a target, rather than a real specification.
A turboprop replacement would be great. But all we see at the moment are turboprops in the tiny RC model aeroplane size, then a big jump from 200hp. There's nothing in between to replace the Rotax 447 and larger in the LSA market. We're all stuck with piston engines in that category.
There are some sub 100hp turbo props
Any idea what the installed weight will be?
I'm not sure sorry. Best to contact Turbaero
270lbs per the company.
This ought to make a nice retrofit for a mooney
I wonder if the "recuperator" is similar to the one used on the old Rover turbine car.
There have been many gas turbine engines with recuperators, and they are all similar in function. There are two physical designs: a conventional heat exchanger as used by TurbAero, and a rotating disk which passes alternately through turbine exhaust and compressor output. Rover's JET1 had no recuperators, their T3 apparently had a conventional heat exchanger for recuperation, and I haven't found details on the later version. The other turbine cars (such as those from Chrysler) tended to use the rotating recuperator.
@@brianb-p6586 I remember seeing a cut-away drawing of a car turbine with a rotating heat exchanger, something like lots of crinkly metal plates in a disc, and the air flowed axially. A bit like the comprex pressure wave supercharger, but different.
I'm quite sure that it was a Rover, but not 100%.
@@joejoejoejoejoejoe4391 that's the rotating design that I was referring to. It might have been one of the later Rover designs - I don't know.
I always understood gas turbines are inherently less fuel efficient than reciprocating ones because the peak pressure/temperature in a reciprocating engine can be much higher than in a turbine one precisely because that peak is only very momentary, unlike a turbine where the HP turbine inlet must operate at a constant temperature. Sure a recuperator will help by greatly cooling the exhaust (ie extract the residual energy from the turbine outlet) but surely this is basic thermodynamics. Large turbines offset this lower Carnot limit by getting closer to it than large reciprocating ones through lower pumping and friction losses, but this is unlikely to be so for small turbines. Of course Turbaero's engine should have other advantages over piston engines, including lower aerodynamic profile, greater power-to-weight ratio, smoothness and inherent reliability, but I am sceptical that you will beat an old fashioned piston engine's fuel economy.
Large gas turbine engines run such high pressure ratios and peak temperatures that their efficiency is comparable to the most efficient gasoline engines (although still lower than similarly large diesels), but small turbines don't even approach that. The Wikipedia page for Brake-specific Fuel Consumption has some good examples.
I've asked TurbAero for some comparison figures to post here
It's compressor section pumping losses that's the big one. So much of the turbine power is wasted through pumping losses that there's not much available for work in comparison to the fuel consumed.
Piston engines for all their shortcomings are remarkably good.
Turbines traditionally were good at high altitude because the higher you go the faster you go for the same indicated airspeed, meaning the time to destination is less so the fuel burn less. Also at high altitude the turbine cycle naturally compresses its own air, the compressor pumping losses are also lower. This all adds up to being efficient in certain commercial situations but until now not so much for non commercial ops.
Ken, you are correct that diesels and spark engines peak temperature yield greater efficiency than a turbocharger simple GT.
As economics allows both pressure (multiple compressor stages) and temperature (via blade cooling) improve GT efficiency. In complex GTs, the max pressure ratio a question of thermodynamically diminishing returns, and the upper temperature boundary is nitrous oxides (~2100F) emissions.
For the low hp turbocharger-simple GA market, we are stuck with ~ 3.5 pressure ratio and ~1300F. The 3.5 ratio is about where a single stage centrifugal compressor goes supersonic; and 1300F is material limitation. Heat recuperation is effective, but at the expense of weight. Low pressure ratio recuperative simple GTs have existed since the late 50’s (Rover, Chrysler, Ford, GM all experimented. Honeywell engine in Abrams tank is recuperated)
Past decade has seen supersonic high pressure ratio centrifugal compressors with shock wave diffusers. Simple GTs with supersonic compressors are flying in helicopters (P&W and RR/Allison & perhaps others). Experiments ongoing with ceramic turbines to increase temperature, but no joy yet.
Simple GT efficiency also suffers from RELATIVELY thicker boundary layers and RELATIVELY broader clearances.
As to our Australian buddies; with them well but not sanguine as to success.
@@danbenson7587 I assume that your strange term "turbocharger simple GT" is intended to mean a gas turbine engine with a single-stage centrifugal compressor... that's not immediately apparent.
How much?
Where can we see a video of the engine running?
Nowhere. They haven't built a running one yet. They're still building parts for the prototype.
If overall Jet A fuel running costs are similar to a piston on 101LL what is the big difference in using a turbine vs a piston ?
TBO
Smoothness, torque curve, and TBO
I wish you succes.
i give these guys credit and i hope they can pull it off, but i think it's highly unlikely.
The Free wheeling turbines have their shortcomings and are very unforgiving when they fail. Plus one will have to get a turbine rating from somewhere (single turbine ratings are not so readily available fro the certified aircraft market like from a TBM 700-950.. ) So after getting a rating on a 500-850hp turbine, you really want to go back to a 200hp turbine? I'd think that development should have been pegged at the 350hp+ market. Now as for Fuel efficient, well that is usually at FL 220+ and cabin heat is sorta needed, plus a mask and an IFR rating.. Down low, you've got a fuel pig that will eat the extra weight of the piston engine in an hour.. What is needed is Liquid Piston to get their shit together and release a version of their engine in a 200hp (150Kwh) version with a turbo boost, or a doubled up 80Kwh combination (so you can loiter on one engine)...
As someone said upthread, when you get all the parts moving in the same direction, it really helps.
@@abel4776 MOSAIC is being opened up for the used aircraft market s my impression.. more so for the Beechcraft V35's and such. to keep a sufficient interest in the pilot development market.. that is my impression (I'm a former owner).
$85k is the target price point! A brand new IO360 is about 40k with core exchange. Any mechanic can work on my Lyc. Non American companies are always pitching kerosene engines to us Americans, as if dudes who shell out 100k for that turbine care about the price of fuel.. Like, dude, just because it ain't available in your countries... Avgas is readily available in America.
How can heating the compressor air make an engine more efficient?
Hot air is less dense right!
You appear to be confusing efficiency with power output per unit of engine size.
For a turbine it makes sense. It doesn't work for piston engines because they are limited by detonation.
As with any recuperator, the heat is added after the compressor. In any gas turbine, compression is followed by heating in the combustion chambers, then by expansion through the turbine. As shown first @1:25 and explained starting @2:16, the recuperator acts as a first stage of heating which doesn't consume fuel, so the effect is simply to reduce fuel consumption for the same power output... and thus greater efficiency.
Heating the air _before_ the compressor would not work for either power output or efficiency.
@@jimosborn390 It doesn't make sense for a piston engine only because there is no practical way to transfer heat into the compressed air in the combustion chamber, especially in the zero available time after the compression stroke and before combustion.
@@brianb-p6586 jimosborn390 is correct. Piston engines heat up the air much higher than a turbine. this is done with the compression ratio. A piston engine has a much higher compression ratio but is limited by pre and post ignition. Piston engines work on pressure, turbine work on flow more or less.
I think I'll wait for the 300 hp Zoche instead. ;-)
I want to indicate this is the most underrated snark and deserves a thousand thumbs up.
The start process is going to have to be idiot proof though. Watching the now "liquid" pieces of your powerplant flowing out the exhaust would be a disturbing experience.
I would like to have a fiddle with the Emulator they have for this turbine and see how fast the fuel tanks drain at "flight training" altitudes. Would also be interesting to see the numbers in the sub FL200s too.
I hope it comes to fruition unlike the Italian ceramic turbine when I was flying a C205 in the early to mid 80s when climbing with a load of skydivers in ISA +20 temps was no fun. Added extra precious time to my logbook though.
Production update?
Not yet, I have contacted the company to request an update.
Given its size, has any thought been given to an automotive application for this Mighty Mite?
It's not clean or efficient enough for automotive use.
There have been many gas turbines designed and built for automotive use, almost all with recuperators, and all have failed due to inefficiency and operational issues. In a series hybrid configuration most of the operational issues would be resolved, but efficiency is still too low. With current requirements, turbines generally have excessive emissions, as well.
There is nothing about this specific design which makes it suitable for automotive applications. That's not a criticism, as it is designed specifically for light general aviation aircraft... not cars and trucks.
That is a very 'neat' engine.
Can someone explain why gas temperature fall when hitting turbine?
Energy is extracted from the gas which results in pressure drop across the turbine. This rapid reduction in pressure results in temperature drop due to
the Joule-Thomson coefficient/effect en.wikipedia.org/wiki/Joule%E2%80%93Thomson_effect
"There is no fuel-efficient turbine engine for this category of aircraft". Heron engines is flying a turbine in a Bristell and Turbotech has a running engine (with recuperator)?
This engines consumes about twice as much fuel as a modern piston engine, so yeah.
Would love to mount one derated to 150-HP in a Piper Tomahawk.
that would make it a true trauma-hawk.
Good to see an Aussie company having a crack. I see these as even being a powerplant option for land based applications.
I agree, great to see an Aussie company on the world stage. Definitely a lot of applications for these.
I don't think there are any applications, especially in land based applications. Companies such as Wrightspeed (with their "Fulcrum" radial inflow, axial turbine, recuperated, 80 kW turbine engine and generator set) have developed similar engines, progressed far beyond TurbAero's current state, and failed to find commercially viable applications.
@@brianb-p6586 I can see this as a combined electric generator and heating system for a house, a small race car power plant, or an engine for a refrigerated truck.
@Chris Henniker combined heat and power systems can be effective, but 200 HP is way too big for a system for a house.
It's also too big for a reefer unit.
Racing class rules are very specific about engines; there are very few if any which allow gas turbines.
@@brianb-p6586 I can see this in a small hot rod.
Isn't the exhaust awfully close to the firewall? To close.
thats damn expensive for just an aircraft egr like system on a turboprop, but than again what I don't know much about exact specs of these thingos
Good luck , sounds good to me😊
This is how you power generators to operate electro-driven trucks and trains. You might put smaller units on Teslas.
350g/kwh compared to 250 for modern piston. 350 is at max power also, economy will be worse at lower power settings.
Comparing dollar for dollar, also take into account the fact that Jet fuel is cheaper than Avgas, about 20% on average. That brings the cost to operate a lot closer ;)
@Richard of Oz You sound like all the turbine people trying to make it sound better by comparing it to an engine from 1930. I'm talking about a modern engine that uses regular 98 petrol. Jet a1 is about 30% more expensive than 98. The turbine uses 40% more fuel at best, and this engine costs about minimum 3 times as much initially as a modern engine. Of all the engines and companies, none have made honest comparisons, they just say it's comparable.
@@chippyjohn1 First, Build it… and they will come.
If it were possible they’d have a working example by now. This exact model has been showcased for 2 or more years now.
They have completed the design phase, beginning prototyping phase...you have zero comprehension of how this works don't you?
@@maddogmorgan1 this engine is simple. A few rotating parts when compared to an ICE or even a transmission. The P-51 mustang was designed and built in 6-8 months…. So it can be done. They’re just treading water with an inept number of people working on the project.
I can imagine RAAUS certifying this, and CASA laughing.
But for an RV 4 or 8 it would do me.
Awesome option for the experimental market!
@@RichardofOz
Yep!
But it took the RAAus decades to lift the stall and increase the weight because Carmody refused everything and the RAAus board were in his pocket, they done nothing to advance sport and recreational aviation.
Experimental won't advance any further, GA is as good as dead.
Fuel is too expensive, maintenance costs are through the roof, and no work ethics anymore.
Hangerage is too expensive even if you can find it.
Local government want their pound of flesh and refuse freehold tital.
Holbrook made a start and it all died at Wentworth when the developers got too greedy.
I wish them luck to actually produce a working prototype
Looking forward to seeing the prototype running!
@@RichardofOz The one that was supposed to be running over two years ago according to their own news releases? Yes, good luck...
I want to drop the 200hp version into a Miata !
No we're talking!
No mention of weight compared to an o320
Not sure, if you contact Turbaero I'm sure they can answer that for you
Ultimately, we won't see the claimed efficiencies; any weight saved by the lighter engine will be eaten up by the jet fuel; you'll need more gallons, and each gallon is 15% more than avgas. My day job is at a company building the most efficient jet engines on the planet, and also the largest. It's not easy-a 5% gain is monumental.
Thankyou for building this.
I have often wondered why the heat exchanger has not been used more often.
May I ask one question?
Could you put the heat exchanger between the two power turbine stages?
This would be at a higher temperature and hence more efficiency but run colder air through the second power turbine. Lower flow rate but denser and colder.
super sir
👍
Read up on the Achates 2 stroke engine..........Cummins diesel makes it for the US Military. 50 to 55% thermal efficiency........no valve train. Can run high compression on any fuel, from gasoline to diesel. Would completely murder a jet turbine on fuel efficiency.
I hope fuel efficient means 400 miles to a gallon.
Wouldn't that be nice!
In this case, "fuel efficient" means not too much worse than the engines commonly used now.
Does anyone remember the ERCO ? (Google, Jessica Cox for ref...)
A plane designed and built in the late 1930's that was last known as the A2 before the company changed hands (Again) to what we know as the Mooney
This was the safest plane ever made and also the most fuel effient even when compared to modern setups .
I wonder how this would go with a revisit, redesign and upgrade to Turbo Prop , with this much power available it could be a 4 seater that is Fast , Safe and extreamly practicle with that economy.
And would look amazing with that classic Twin tail ...Maybe?
Ok probably just me but I like the Twin Tail setup , it's like the spair tyre on a 4X4 it just goes there.
This could save Cirrus from the out dated engine they have a sick fasination with too
Sure, it's possible. But, let it also be under 100 pounds total all up....that's the ticket to shoot for.
So no working model. Be nice to see the model run.
Soon. The prototype is being built currently.
You lost me at 85k😂
It's amazing how most initial improvements to efficiency in torque converters, through P.R.T. on radials etc., are the number of the universe. In the human body, 20 minutes is the basic cycle and many other things. 20/20 perfect vision, lowest one can hear 20 hz, most 20khz (all on average in all for average adult). Average adult has about 20 square feet of skin...
the only number they won't get close to is the sale price, it's gonna be over 100K I'd bet ;/
…Experimental helicopters?
All good…but these engine and aircraft “under development “ are always an unknown and most never become a reality and investors money is usually lost forever.
NOW!!!
Sorry but at 12.5 gal/hour at cruise altitude, it is 25% more fuel burn than a conventional airplane engine. Sure it can produce more horsepower but lets hope the airplane is designed to fly at more than 250knotts
You are talking about your typical four-cylinder, 360 cubic inch piston engines which burn at roughly 10 gallons per hour. But, these produce only 180 horsepower. The only things coming anywhere close to 250 knots are powered by larger, six-cylinder, 540 and 550 cubic inch engines burning much more fuel. So, this may be a good compromise of lower lead emissions, lower maintenance time, lower per gallon costs, etc.
@@deanfowlkes There is no lead in the future because the FAA has approved at least one non-lead avgas. More are coming. I have no problem of experimenting with new propulsion system but to say this is the same as piston is stretching it. Turbine burns more fuel, period. Turbine is efficient at higher altitude based on the speed they can fly, and turbine aircraft are generally larger so they can carry more fuel. The smaller general aviation airplane are generally designed to carry about 40 gals of fuel and when they are leaned, they burn less than 10 gal/hour. Burning 12.5gal/hour is at least 25% or more than conventional avgas.
@@2Phast4Rocket - If you notice, I never disputed the claim of the turbine having a 25% greater fuel burn. I stated the trade off may be worth it. You absolutely can get a better than 10 gallon per hour fuel burn at cruise burning lean of peak at altitude. I used to fly an old C172M with a constant-speed STC that could really sip fuel (comparatively). Rotax powered aircraft can get in the 5-6 gallon per hour range at the expense of horsepower and useful load.
As far as non-lead Avgas, that is on its way. Unfortunately, it is brand new. Even in an area that is serviced by a major Class B and several D, E, and G airports, there are none that have the new unleaded. It will be years and maybe decades before it is widely available. It may never be widely available worldwide. 100LL is becoming a scarcity outside of the US.
You guys do realize they wouldn’t burn avgas but could just burn Jet fuel, aka kerosene with freeze agents. The only advantage I could see of this is increased altitude if the cockpit is pressure rated. It can take advantage of the thinner air and higher air stream speeds and optimally cruise at a higher rate of speed. Thus the fuel consumes per hour would net you greater distance. So at the end of the day. It’s all about the airframe. If it can’t handle the speed and altitude requirements. Not worth it. Unless you want that turbo prop engine sound I guess. I mean it’s their own aircraft. If your willing to get Willy with your power plant, why not give it a shot if you got the moola.
@@egondro9157 - We do realize that piston-props burn Avgas or the new No-Lead and turboprops burn Jet A. That is where the debate lies. Is it worth it. Avgas costs more than Jet A. No-Lead will more than likely cost more than Avgas. I don’t know that for a fact since none of my local airports carry the No-Lead, yet. Factoring the cost of the fuel, the claimed fuel burn, and the claimed maintenance intervals, this engine may be a viable alternative.
The M1 Abrams could use this tech
Why? It already uses the Honeywell AGT1500 that has this recuperator tech.
Uhh dark aero!! They are close to flying their plane soon ! Perfect for this engine! Uhh Rolls Royce has a 250 that cost through the roof!!
The UL Power UL520iS used in the DarkAero design is smaller, lighter, and more efficient than the claimed dimensions and performance of the TurbAero TA200... for the same peak power. Since TurbAero only claims any advantage at high altitude and the DarkAero is unpressurized, the turbine would be unsuitable in every way except for vibration.
This is taken directly from the Chrysler turbine engine from the 1960's, and it's stupid. You're basically taking a 1000HP capable turbine and reducing the power output to 200HP by pre-heating the air. Just use a smaller turbine. If 200 HP is your goal, a large hobby jet engine will do the job.
What hobby turbo shaft jet engine produces anywhere near 200hp?
No, that's not how it works. The air is not being preheated (before the compressor), the first stage of energy input is from waste exhaust heat rather than burning fuel.
@@brianb-p6586 re-read what you just wrote. The exhaust is pre-heating the intake air. Look up the "re-generator" from Chrysler. The hotter the air, the less molecules, the less fuel that is needed. Ie. You produce a lot less power for a little fuel savings. Chrysler claimed it was because you don't need to waste energy to heat to incoming air and therefore save on fuel. However you want to look at it, it's the same thing from the 60's. I would recommend just using a smaller turbine. Something the size of a large turbo could produce 200 hp and use less fuel.
@John Doe I know what I wrote, but you seem to not understand it or how a gas turbine functions. In a Brayton cycle (of which a gas turbine is the most common example) after the compressor heat is added in an isobaric section, followed by expansion in the turbine section. Thermodynamically, it doesn't matter if the heat is added by combustion of fuel or transfer through a heat exchanger, although pressure drop due to flow resistance in any part of the flow path is undesirable.
Ditto. You need to look up the basics.
No scale drawing or physical cutaway of the engine makes me suspicious.
They haven't even built one prototype yet, so there's no cutaway. Renderings of the internals would be good, but I wouldn't expect internal dimensions from any manufacturer, especially of a product not yet in production.
RUclips recommended a video about another similar engine which appears to actually exist: the TP-R90 from Turbotech SAS of France (search for "turbotech-aero"). Their product page shows a cross section; the TurbAero engine is probably very similar.
I am to old to believe this
'Fuel efficient turbine'
Never seen someone crack a buggywhip so hard in my life.
Good thing the corps is feeling no pain.
It's fuel efficient FOR A TURBINE, but you're still getting less power for more fuel than you would with a piston. Could be a step in the right direction though, who knows what will happen in the long run?
@DiveForKnowledge it's actually not good for a turbine, but might be good for such a small turbine.
@@diveforknowledge Gas turbines are INHERENTLY less efficient that reciprocating engines, because physics. Google "Carnot efficiency". That aint gonna change unless the Second Law of Themodynamics changes.
Um,,, even if they exceed their power goals and production costs… There is going to be some effort to keep them out of the market; by competitors, bureaucrats, and fuds who don’t like anything new.
The flying car was invented and successfully flown in 1947…
Engine uses recuperator because compressor has not enough compression ratio. Wrong direction.
Still very pricey at $85,000.
$$$???
He said $85,000 but hedged that that may increase.
He said $85,000.
That is a dream price. It WILL be higher. Much higher. Probably at least double.
Look at Icon A5......went from $129,000 to nearly $400,000.
@@davem5333 Because they can!
You may get that pressure I'll tell you your engine life will be very much diminished and you're also up for possible catastrophic event
Here is the answer. NO it is not possible.
Another year, and another non-working display model. 4 years (according to video) and not one running prototype yet. WTH?
Where’s the beef?
I’ve been waiting for a 200hp turbine since 1996
Aviation is so sad today
No innovation just scams
pipe dream
If it were easy to recoup an additional 20% of useful work by installing a recuperator, with acceptable weight, complexity, cost and service life trade-offs - everybody would be doing it. In fact, OEMs would be jumping at 2%, let alone 20%. Yet, nobody is.
I honestly wish these guys best of luck, but my skepticism is very strong.
While the efficiency improvement is plausible, I agree that other factors make it difficult to incorporate a recuperator. Recuperators are routinely used by established gas turbine engine manufacturers, but not in aeronautical applications... and not even in many stationary applications (where fuel is cheap).
I have just run across another new gas turbine engine manufacturer who is a few years ahead of TurbAero and is using a similar recuperated design: Turbotech SAS (of France, look for "turbotech-aero"). Their engine is at lower power (90 to 100 kW continuous, rather than 150 kW), and is targeted to replace Rotax installations. It has not been successful yet.
Small turbines have a low compression ratio so the air is not heated as much as larger turbine engines. The mass of air flowing through is also much lower so there is less air to heat up. With a large turbine that already has a high compression ratio it is not needed, plus it would restrict incoming air, plus the volume of air would require a very large recuperator.
The future isn't Fossil Fuel engines!
The future is electric flight ✈️
Yeah... not happening...
I thought you were going to be flying by this time from previous comments last year. It looks like a mock up. I predict it will never fly.
Allison Model 250, now Rolls-Royce M250 is the logical choice for small turboprop for a fixed wing plane (about 300-420 HP).
Built a plane that can handle a PT6 (550 to 1600 HP), Garrett TPE331 (575 - 940HP).
@@DylanClements98 The dream of turbine. I have flown turboprops and jets professionally. Great for commercial, military and rich people, corporate jets and turboprops. For GA pilots, private owners, who are not wealthy, flies well 100 hours a year, a piston under 350 HP is great. You can buy used jets cheap but cost of fuel and maintenance everything else is astronomical. Fuel is not measured in MPG but Gallons Per Mile. (Jets use fuel in pounds but the point is... thirsty.)
Their "economizer" is not a new idea. Their mock up has one in plastic 3D printed. The predicted power and fuel flow numbers out of thin air, wild guessing. Again the Allison Model 250, now Rolls-Royce M250 has been used in helicopters and a few fixed wings, including P210 and Beechcraft Bonanza turboprop conversions. They are OK but the airframe is speed limited and for the cost it does not do much more than a Continental IO550 turbocharged engine. Years ago you cold get Allison 250's out of APU Generators and convert them. You are far better buying an old TBM750 with a PT6 with some time on it (and pre purchased inspected to assure no cracks in combustor or other expensive issues). Before the pandemic you could get one for $0.75M and have a real plane that can do things.
I know a Sonex Jet owner/pilot. The SubSonex as they call it uses a tiny drone jet. It has to be overhauled every 250 hours I recall. It is an oversized RC jet engine. It takes a long runway to get in air. Once up it scoots along but not for long, it has a range of only a few 100 miles, like the BD5J. Cool plane but a single seat toy, very cool toy but still. However if that is your dream go for it. However that turbine dream will not be powered by this TurbAero engine... nope. TurdAero. Ha ha.
The Allison/Rolls Royce engine tops out around 450hp and was designed as a helicopter engine. Runs out of guts over 12,000 feet or so.
And costs in the $400,000 range.
No way this engine will be $85,000.
Other than fuel costs, I see no advantage to this engine and only down side to operating it and maintenance.
Despite lower fuel price, total fuel cost will be higher due to the high consumption.
That turbine sound though! and bragging rights at the pub haha
Like some guys in a garage are going to build a turbine....... Promise people what they want to hear and they'll give you their money.
Hey fellas....I'm not shelling out 85K for any 200HP engine I don't give a rats ass if its been dipped in 24K gold sorry mates .. nice try ....
Turbine? Fuel efficient? Ha!
Cool. Really looking forward to watching this fail just like every other "modern" GA engine for the last 50 years.
talk is cheap... let us know when you got a engine approved by the FAA