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" APPROACHING THE SPEED OF SOUND " AVIATION AT MACH 1 SHELL FILM UNIT EDUCATIONAL FILM 74842
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- Опубликовано: 20 июл 2015
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Created by the Shell Film Unit, "Approaching the Speed of Sound" . The Royal Air Force commissioned Shell to make these films to detail hazards and physical issues related with high speed flight. Peter de Normanville directed the film; he served as scientific director of London Shell Film until 1963. He utilizes a process known as Schlieren technique using vivid colors to show shock waves built up on the aircraft's wing and tail surfaces as it flows through the sound barrier. The films in this series were considerably successful; hundreds of copies were sold and it won numerous prizes. It is comprised of a series detailed diagrams and animations showing the relationship between speed of the aircraft and the speed of sound and shots of planes approaching Mach 1 or the speed of sound.
The film opens on the Shell logo (:10). It was created by the Shell Film Unit (:33). An RAF Vulcan Jet zooms onto screen (1:46). The film begins with a series of demonstrations on how sound travels through the air (1:59). A slinky is first used (2:20). Sound waves are compared to ripples in the water (2:39). An explosion is set off (2:59). The speed of the aircraft and the speed of sound are compared (5:27). The nose of the Vickers Valiant B MK-1 bomber (5:40) appears. Mach number is discussed (5:47) and the Mach meter is shown (6:03). A diagram details how Mach number is calculated (6:12). A wing section is used to show drag (7:31). A Blackburn Beverly (9:21) flies onto screen. Flight Mach number (9:48) and local Mach number (9:59) are compared. Shots of the pilot follow within the cockpit (10:58). On the gear panel, the flight Mach number is noted to have been altered (11:11). Shaky footage captures the aircraft buffeting violently (11:24). A high speed wind tunnel is used in example (11:53). The compressed air jet is turned on showing spurts of blue and red (12:23) detailing increasing and decreasing density (13:25). Shock waves are visible as a missile spins through the air (14:47). Still footage shows the shock waves better (15:07). A diagram explains what happens when the craft reaches critical Mach number (15:40). Wave drag is explained (18:04). The meter appears as it approaches the speed of sound (18:34). The pilot grips the controls as he experiences loss of stability within the cockpit (19:17). Wool tufts are stuck on the wing for this experiment to show separation in flight (19:27). Hues of blue show the speed up of air around the aircraft (19:57). Shock waves lead to an increase in drag (20:09). How to combat or avoid drag is covered (20:31). The Folland Gnat (20:36) and the Avro Vulcan (20:43) swim on screen. The thin wings are employed on the crafts in order to help reduce drag. As speed increases the shock wave forms (21:19) around the thicker wing. Mach number .9 is displayed (21:44). The Vickers Valiant (21:58) zooms above. A wing is used to show air flow changing as the wing is swept back (22:27). A Northrop jet zooms over (25:11). A Fairey Delta 2 mid-wing tailless delta monoplane appears in flight (26:03). A Boeing 707 passenger jet (26:20) follows. The shell logo closes the film (26:46).
This film is part of the Periscope Film LLC archive, one of the largest historic military, transportation, and aviation stock footage collections in the USA. Entirely film backed, this material is available for licensing in 24p HD and 2k. For more information visit www.PeriscopeFi...
Not only the golden age of aviation but the golden age of aeronautical educational content. 👏
British I might add!
That wonderful 50’s sense of romanticism and charm never ages. 👍🏻
Fascinating. Brilliantly illustrated!
The wind tunnel tests showing the formation of shock waves on the airfoil section are very enlightening.
Perfect old style explanation! Easy to digest!
When I was a kid my dad was trying to tell me about speed of sound ,,,about a week later I was watching a friend bouncing a basketball a half block away ,i didn't hear the ( bounce ) until the ball got back to his hand ,,, aaahaa ❤ now i get it !
Amazing!
Thank you very much for this magnificent piece of engineering history!
Glad you enjoyed it! Please subscribe and consider taking a deep dive on our submarine of film preservation at www.Patreon.com/PeriscopeFilm
Thank you for uploading this video. By the way, some of the illustrations are remarkably didactic.
Glad you like them! Help us save and post more orphaned films and get the inside scoop on Periscope Film! Support us on Patreon: www.patreon.com/PeriscopeFilm Even a really tiny contribution can make a difference.
Very informative and easy to follow.
Dr Zoom and the Sonic boom! 💥
It was viewing this film in Physics Class CIRCA 1965 that got me into aviation.
I gotta hand it to those early test pilots, The balls one needed to push these barriers was planetary.
thanks
That was great !
Thanks.
Outstanding video
VERY GOOD .. THANK YOU.
Very good film
Is that a Blackburn Beverly at about the 9:20 mark? I had the pleasure of going through the last one of them at Fort Paull, near Hull, England while visiting friends there.
1950's corporations should run the public schools. Shell, Bell Labs, IBM, GM... sure we lose environmentalism, but at least our kids would understand more science than ideology.
After such an eloquent reasoning... the last paragraph should read: "At high altitudes the speed of sound is lower because of the lower air density."
Incorrect - for a gas. See above explanation of the equation for the speed of sound in a gas. Here is a link that explains the speed of sound in different materials. www.nde-ed.org/EducationResources/HighSchool/Sound/speedinmaterials.htm
@@dougball328 He's not quite incorrect though is he. Air density is important and sound does travel faster through denser air. This quote from your link,
"Suppose that two volumes of a substance such as air have different densities. We know the more dense substance must have more mass per volume. More molecules are squeezed into the same volume, therefore, the molecules are closer together and their bonds are stronger (think tight springs). Since sound is more easily transmitted between particles with strong bonds (tight springs), sound travels faster through denser air.
However, you may have noticed from the table above that sound travels faster in the warmer 40 ^{\circ} C air than in the cooler 20 ^{\circ} C air. This doesn't seem right because the cooler air is more dense. However, in gases, an increase in temperature causes the molecules to move faster and this account for the increase in the speed of sound."
@@ianrkav The speed of sound is the square root of the product of gamma * R * T where gamma is the ratio of specific heats, R is the gas constant and T is the temperature. Please notice that density is not in the equation. This equation is for gases only - and different gases can have a different R. You correctly pointed out the flaw in your own density argument when you noticed that the speed of sound went up on warmer gases. CORRECT !
@@dougball328 Well you did mention a 'constant' there:-) Speed of sound at 30,000ft is about 660mph. At sea level about 760mph. Why? Just because density isn't in the particular equation you mention doesn't mean it isn't a factor, but for that particular gas equation you would be correct:-) But so is the other guy:-) Anyway, thanks for your fast response from a four year old post.
@@ianrkav I repeat, the density doesn't matter. You could cool the air down at sea level and the speed of sound would drop even if you kept the pressure the same. And yes, because density is not in the equation DOES mean it isn't a factor. As a 40+ year aeronautical engineer, I know this subject far better better than you. Sorry, but that's a fact. Now I am done wasting time trying to educate you. I suggest you get some books on gas dynamics and study.
Somebody help. The speed of sound depends on material or
fluid density: the denser the material the higher the speed of sound (think
putting your ear on a train track...). At sea level the air is denser and
therefore the speed of sound is higher than at high altitude (any altitude)
because the air pressure is less. Yet at 3:20 - and this
is not the only youtube location where I find this stated (!), it is said that
the speed of sound depends on temperature, and because the temperature is
lower, so is the speed of sound. The opposite is true: the lower the
temperature the higher the air density, so the higher the speed of sound. At high
altitudes the speed of sound is higher because of the lower air density (the
temperature may have a negative but not linear contribution, and I am sure there
are plentiful studies).
Interesting
For a gas, the speed of sound is the square root of (gamma*R*T), where gamma is the ratio of specific heats, R is the gas constant, and T is the temperature.
@@fiftystate1388 It's not rocket science. In a GAS, the molecules are not touching- so to transfer mechanical energy, the speed of the individual molecules sets how fast a wave can travel through it and the speed of the molecules is set by the temperature. The higher the temperature, the faster the molecular motion and the faster sound propagates because that's how fast one molecule can move to hit the next molecule in succession. As the *density* varies, the distance the molecule has to travel is less, but that has nothing to do with the molecular _velocity_. More precisely, a shorter path has a minor effect on the speed of sound, but in a gas it is a tiny effect compared to the effect of temperature.
In cold gas the density might or might not be higher- but the molecules STILL are not touching each other and the speed of propagation is less because the speed of each molecule is less and they take longer to bump into the next one in succession. Get it? Don't assume that because the gas is colder it is denser- density is a variable that is usually NOT connected to temperature in the atmosphere; the higher you go the air gets colder but it ALSO gets LESS dense. Stay with me...
In liquids or solids, the molecule ARE touching...so the "mean free path velocity" has no effect because there IS no free path. Higher gas temperature means higher free path velocity. (The "mean" free path velocity means AVERAGE velocity. There is some distribution of velocities because, like billiard balls during a break, some move faster and some move slower. But that's simply a detail of the statistics.)
Be careful extrapolating from what you THINK you know. Because sometimes you over-reach. This is one of those times.
Remember: Mach numbers only apply to GASES. NOT liquids and NOT solids. Only where a molecule has to travel some distance to hit another molecule does the Mach concept apply.
Consider the speed of sound is faster in steel, per Bing search, 16,400 FPS. I wondered about air Temperature vs Pressure too.
Wow, modern education really has degraded badly. this is far superior to education today.
It been bad since the 60s
Anyone know who narrated this film? I've been hearing this guy's voice for decades and always wondered who it was.
Troy McClure
I'm pretty sure that's Ed Reimers, the 'You're in good hands with Allstate' guy. Here's another of his voiceover jobs: ruclips.net/video/Kp4qebb16cw/видео.html
It was Donald Trump
You didn’t know that ???
Sounded American or Canadian - slightly at odds with the all-British aeroplanes !
How do we get rid of the irritating clock at the bottom?
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In the past we tried many different systems including placing our timer at the bottom corner of our videos. What happened? Unscrupulous RUclips users downloaded our vids, blew them up so the timer was not visible, and re-posted them as their own content! We had to use content control to have the videos removed and shut down these channels. It's hard enough work preserving these films and posting them, without having to spend precious time dealing with policing thievery -- and not what we devoted ourselves to do.
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American accent, British birds (as a rule), a bit odd.
There's two versions of this, The other one has the British narrator and the british credits. Also this is only part one of a three part series.
High Speed Flight - Part 1 - Approaching the Speed of Sound
High Speed Flight - Part 2 - Transonic Flight
High Speed Flight - Part 3 - Beyond the Speed of Sound
Here's the British one, much better copy.
ruclips.net/video/jfic0f0eJm4/видео.html