the angle between free stream relative airflow and downwash is called " the induced angle of attack". There is one question in ATPL. Now you know the answer. Thank you flight-club, again.
It is actually the angle between the free stream relative airflow and the effective (local) airflow that is the induced angle of attack, not between the free stream and the downwash, no?
I discovered that Parasite drag is produced by VERTICAL surfaces and Induced drag is created by HORIZONTAL surfaces, for example when the Flaps are at 0 degrees they produce Max Induced drag and Min Parasite drag, at 90 degrees Min Induced and Max Parasite drag and at 45 degrees in the middle of both. Please let me know if you think it is a valid observation. Thanks
It seems to me that even without vortices causing downwash and a local airflow, at almost any substantial angle of attack the lift vector of the wing is going to be pointed slightly backwards and therefore there will be a component of that lift force pointing backwards, causing drag. The local airflow from the vortices simply increases the tilt of the lift vector backwards even more.
wow ! ever since i learnt about induced drag i used to visualize by myself that how does vortices affect airflow but always had a slight confusion but today its crystal clear nd will never forget in my life.☺
The problem I have with your illustration of spanwise flow is that I observed just the opposite. I placed a camera behind the main wing of a model plane that I flew in light rain. Drops of water small enough to fit within the boundary layer on top of the wing could be seen moving outward from the fuse, not inward.
This channel helps me a lot but I have never gave it a thumbs up. And I'm truly worrying about that but instead of doing like that I'm pretty sure that so many people like me keep the channel under subscriptions 😘😘. Simple and clear explanations with graphical illustrations. Superb!!❤❤
Could someone please help me understand why the wingtip vortices, which cause downwash of the airflow behind the wing, affect the local relative airflow at the wing itself? I don’t get why the airflow in front of the vortices should be affected.
So if newtons third law explains that since air is deflected down and back from the trailing edge there is an equal and opposite reaction force upward and forward, then why does the effect of induced drag that further bends the downwash downward not result in the creation in more lift. In theory air is being deflected more downwards and would that not therefore mean the equal and opposite reaction to the downward directed air be upwards even more? I dont think induced drag and wing vortices increase lift, but this logic tells me it does. Where am I going wrong? I must be misunderstanding something
1- To maintain steady level flight, as speed increases we have to reduce lift to maintain level flight, so we reduce angle of attack, reduction of AOA will lower the induce drag. (remember the main cause of induced drag is AOA) 2- Induced drag decreases with increasing speed (for a constant lift force). This is because, as speed increases, the downwash caused by the tip vortices becomes less significant, the rearward inclination of the lift is less, and therefore induced drag is less.
@@benedictrehiesi5166 Close, but if lift is reduced in level flight, then a descent will occur. I believe what you meant was angle of attack is reduced as speed increases to maintain a constant lift force. The lift equation tells us that angle of attack and velocity are two things we can control in flight to change the amount of lift that is produced. You are correct in your points otherwise.
But there’s something I dont get… there are two things here which produces drag. First the vortices at the wing tips due to pressure differences, which it seems to steal eneryg from the forward movement of the aircraft. And secondly, the fact that the lift force acts tilted backwards because of the angle of attack, which also causes drag, nonetheless, I would say this is a type of “form drag”, as its principle it’s the same. Then, which is the actual induced drag? Both of them together? Because for me it seems like one is independent from the other but both cause drag. Someone help me…
Don't quote me on this, but the rearward aerodynamic force is a product of the local airflow created by the downwash. I'm no physicist, but the two go hand-in-hand, and a frustrating pairing at that.
Quote from NASA "The downstream component of the force is called induced drag because it faces downstream and has been "induced" by the action of the tip vortices." Without lift, we don't get vortices, and without vortices, we don't get downwash, without downwash we don't get that rearward component of lift opposing the direction of flight and causing drag, (named induced drag). So this downwash isn't the result of the wing shape passing through the air. But in fact, downwash is the result of lift, hence 'Lift Induced Drag'. Hope I've helped :)
Tobmy understanding they are synonymous. Both are the same thing, just different explanation. The induced drag is created by the increased aerodynamic lift's component due to the tilted local airflow, and this decreases the efficiency and steals the evergy from the engine. Both outlooks of the physical mechanism of induced drag are synonymous, mentioned also in Anderson's textbooks
So basically the high pressure going to the low pressure is like a car going into oncoming traffic and hitting the oncoming cars, that is induced drag in a example form?
This explation is exactly right. The magnitude of the induced drag is D = (Lift /span)² ÷ q π where q is ½ density speed², called dynamic pressure π = 3.1416 high induced drag at low speed low induced drag at high speed high induced drag in a steep turn. high induced drag with a short wing high induced drag with heavy load
Absolutely great. Short, crisp, to the point.
Much appreciated!
the angle between free stream relative airflow and downwash is called " the induced angle of attack". There is one question in ATPL. Now you know the answer. Thank you flight-club, again.
Cheers and Wish you all the best for your ATPLs !
I'll never be an ATP but I will take the knowledge test just for the joy of accomplishment.
Thank you....I think I knew that...but maybe not.
It is actually the angle between the free stream relative airflow and the effective (local) airflow that is the induced angle of attack, not between the free stream and the downwash, no?
I discovered that Parasite drag is produced by VERTICAL surfaces and Induced drag is created by HORIZONTAL surfaces, for example when the Flaps are at 0 degrees they produce Max Induced drag and Min Parasite drag, at 90 degrees Min Induced and Max Parasite drag and at 45 degrees in the middle of both.
Please let me know if you think it is a valid observation. Thanks
Actually the "downwash" as you call it, it's the effective relative airflow/wind
Wow! Best explanation I've seen so far, and far better than in any of the textbooks. Thanks!
It's been almost 5 years to understand induced drag clearly. And this clip helps me out. I claped my hands after watch this.
Yes, the illustrations explains clearly and immediately. Thank you! Now I understand
Wonderful!
It seems to me that even without vortices causing downwash and a local airflow, at almost any substantial angle of attack the lift vector of the wing is going to be pointed slightly backwards and therefore there will be a component of that lift force pointing backwards, causing drag. The local airflow from the vortices simply increases the tilt of the lift vector backwards even more.
wow ! ever since i learnt about induced drag i used to visualize by myself that how does vortices affect airflow but always had a slight confusion but today its crystal clear nd will never forget in my life.☺
Excellent, thank you for posting.
My pleasure!
I'm only just now realizing I wasn't properly understanding induced drag until seeing your video. Thanks so much!!!
Glad I could help!
Best explanation and visual representation I’ve seen! Thank you
Probably one of best and simplest explanation.
Thanks for the amazing explanation 😀 please make your next vedio on sweepback wings
Ha, you read my mind: we are actually working on this topic. Thank you!
Your videos are so helpful! Your graphics make these concepts so much easier to understand. Appreciate your channel.
Happy to hear that!
The problem I have with your illustration of spanwise flow is that I observed just the opposite. I placed a camera behind the main wing of a model plane that I flew in light rain. Drops of water small enough to fit within the boundary layer on top of the wing could be seen moving outward from the fuse, not inward.
Good information and perfect illustrations video
Many many thanks
This channel helps me a lot but I have never gave it a thumbs up. And I'm truly worrying about that but instead of doing like that I'm pretty sure that so many people like me keep the channel under subscriptions 😘😘. Simple and clear explanations with graphical illustrations. Superb!!❤❤
Can’t wait to present it to my students! 😉 straight forward explanation. Loved it
What an excellent explanatory video! Bravo! Instant-Sub!
This is the best and pure knowledge. Thank you!
Glad you think so!
Fantastic, thank you
Thank you too!
underrated video
Superb! Pls make a video on how local AoA changes on dihedral wings of an airplane in a sideslip.
Great idea! You might like this: ruclips.net/video/WlwxH9SuH5M/видео.html
Thank you😊
After watching this video by brain is a vortex. What creates the horizontal flow 90 degrees to the relitive wind? Just the pressure difference?
Excellent presentation !!
Many thanks!
Great explanation
Glad you think so!
nice
Perfect video, thank you so much
Glad you liked it!
Very Nice.
Many many thanks
Amazing
Thank you! Cheers!
Awesome!!!!!!!!
Thanks!!
A day of reading explained in a 2 minute video :)
Could someone please help me understand why the wingtip vortices, which cause downwash of the airflow behind the wing, affect the local relative airflow at the wing itself? I don’t get why the airflow in front of the vortices should be affected.
So if newtons third law explains that since air is deflected down and back from the trailing edge there is an equal and opposite reaction force upward and forward, then why does the effect of induced drag that further bends the downwash downward not result in the creation in more lift. In theory air is being deflected more downwards and would that not therefore mean the equal and opposite reaction to the downward directed air be upwards even more? I dont think induced drag and wing vortices increase lift, but this logic tells me it does. Where am I going wrong? I must be misunderstanding something
what is local airflow exactly???
good explanation, I'm still no sure why induced drag diminishes as speed increases
1- To maintain steady level flight, as speed increases we have to reduce lift to maintain level flight, so we reduce angle of attack, reduction of AOA will lower the induce drag. (remember the main cause of induced drag is AOA)
2- Induced drag decreases with increasing speed (for a constant lift force). This is because, as speed increases, the downwash caused by the tip vortices becomes less significant, the rearward inclination of the lift is less, and therefore induced drag is less.
@@benedictrehiesi5166 Thank you for very simple explanation. Finally I understood what is induced drag
@@benedictrehiesi5166 Close, but if lift is reduced in level flight, then a descent will occur. I believe what you meant was angle of attack is reduced as speed increases to maintain a constant lift force. The lift equation tells us that angle of attack and velocity are two things we can control in flight to change the amount of lift that is produced. You are correct in your points otherwise.
But there’s something I dont get… there are two things here which produces drag. First the vortices at the wing tips due to pressure differences, which it seems to steal eneryg from the forward movement of the aircraft. And secondly, the fact that the lift force acts tilted backwards because of the angle of attack, which also causes drag, nonetheless, I would say this is a type of “form drag”, as its principle it’s the same. Then, which is the actual induced drag? Both of them together? Because for me it seems like one is independent from the other but both cause drag. Someone help me…
Don't quote me on this, but the rearward aerodynamic force is a product of the local airflow created by the downwash. I'm no physicist, but the two go hand-in-hand, and a frustrating pairing at that.
Quote from NASA "The downstream component of the force is called induced drag because it faces downstream and has been "induced" by the action of the tip vortices."
Without lift, we don't get vortices, and without vortices, we don't get downwash, without downwash we don't get that rearward component of lift opposing the direction of flight and causing drag, (named induced drag).
So this downwash isn't the result of the wing shape passing through the air. But in fact, downwash is the result of lift, hence 'Lift Induced Drag'. Hope I've helped :)
Tobmy understanding they are synonymous. Both are the same thing, just different explanation. The induced drag is created by the increased aerodynamic lift's component due to the tilted local airflow, and this decreases the efficiency and steals the evergy from the engine. Both outlooks of the physical mechanism of induced drag are synonymous, mentioned also in Anderson's textbooks
what does the yellow arrow represent?
That's LIFT.
Where is induced drag smallest? Tip, Root, trailing edge or leading edge?
So basically the high pressure going to the low pressure is like a car going into oncoming traffic and hitting the oncoming cars, that is induced drag in a example form?
👍👍👍
Why Doesn’t the downwash of air due to the vortices create lift? Newton 3rd law
thats a great question
Well it may be creating lift but in an undesirable direction (force acting against the desired lift action).
Wow
so then why does induced drag reduce as you increase speed
Because the vortices have less time to form
This explation is exactly right.
The magnitude of the induced drag is
D = (Lift /span)² ÷ q π
where q is ½ density speed², called dynamic pressure
π = 3.1416
high induced drag at low speed
low induced drag at high speed
high induced drag in a steep turn.
high induced drag with a short wing
high induced drag with heavy load
Wtf it hit me like a rock
*I L I K E P L A N E S* (and rockets space planes are Y E S)
☠️
2:02
The downwash is the lift force.
Great explanation, thanks a lot! 🫶🏻