The Holy grail of Aircraft Development. Laminar Flow Aircraft for up to 30% fuel saving in Aviation Industry @AviationNation My Apologies. Its the B-24 Liberator.
Пікірлер: 493
@AriCat777 Жыл бұрын
It's a B-24 Liberator.
@ElectricAviation Жыл бұрын
My apologies. I had written B-24 on the script but for some reason kept reading it B-54. I guess I had too much of the P-51 Mustang on my mind.
@michaeldose2041 Жыл бұрын
@@ElectricAviation It's ko I have bouts with dyslexia too.
@arturoeugster7228 Жыл бұрын
@@ElectricAviation There are four methods to reduce skin friction; high Re numbers, which destabilizes the laminar boundary layer at high Re and was the motivation for Werner Pfenninger at the ETH Zürich to introduce suction to prevent the instabilities , rolling flow emanating in the 45° clip like vortices to cause transition. below the turbulent boundary layer, a laminar sublayer always exists, on a uniform pressure distribution, according to Ackeret, the thickness of this sublayer grows proportional to the square root of the distance x reducing the shear friction tau = mü× du/dy. the velocity u is of course in the sublayer linear with the height y. That is a reduction of the velocity gradient du/dy, the viscosity mü is indeed a function of temperature, decreasing by a factor of (T/To)^ .78 together with the running length x increasing the Rex = U× rho × x ÷ mü That is the Reynold's number effect. It is now clear , that in supersonic flow, the increase in temperature decreases the skin friction caused always by the sublayer gradient and viscosity. together with the wave drag reduction, (Ackeret's relation 1/sqrt(M²-1) ), the drag coefficient reduces with increasing Mach number ( which BTW was coined by Ackeret in honor of Ernst Mach) .. After wind tunnel testing at ETH, Pfenninger went to Northrop to realize the concept of suction on a highly modified B-66, the X-21, partially succesfull. The pressure distribution determines the velocity at the top of the boundary layer and is close to the potential flow, calculated for the airfoil shape AND the angle of attack. Using conformal mapping techniques or singularity distribution techniques . The Stratford pressure distribution produces a shape, where the velcity gradient du/dy is zero after the maximum velociy distribution, the boundary layer just short of separation all along the pressure recovery region to the trailing edge. This fact was used by Liebeck to construct his famous airfoil sections resulting in L/D ratios around 600, the best ever achieved with initial laminar boundary layer stabilized by a negative pressure gradient dp/dx followed by a transition triggering postive gradient to full turbulent boundary layer and then by the Stratford zero skin friction pressure distribution, just barely stable TURBULENT B.L. pressure recovery to the trailing edge. No too sensitive to AOA. This idea of enormous reduction of the turbulent boundary layer skin friction by near Stratford stable pressure distribution with a very small friction coefficient cf is by far better than trying to maintain laminar B.L. in a positive pressure gradient flow with suction. Talk to Liebeck , at Boeing !
@arturoeugster7228 Жыл бұрын
@@ElectricAviation By the way, it was Pfenninger, who first designed and tested the Celera like body shape at the ETH, called the Zürich body, drastically reducing the drag coefficient in a rather LIMITED Reynolds number range . The data is available from the Institute of Aerodynamics at ETH or in the famous book by Sigmund Hoerner, Fluid dynamic drag, on the graph , skin friction of bodies of revolution, were it is called Zurich body, but no image is shown. So the original publication is recommended, from ETH, remarkable is the shape of the tail end, obviously not on the aircraft, with the pusher propeller. Talking propellers, the contra rotating coaxial propellers have a much better propulsive efficiency , 92+ % , compared to large 4 blade Hamilton Standard propellers, peaking at 85% , due to the angular momentum recovery The efficiency of GA smaller propellers is in the order of only 76% for controllable pitch ones
@arturoeugster7228 Жыл бұрын
@@ElectricAviation The reason, moderately swept wings are difficult to achieve natural laminar boundary layer of NACA 66216, 66212 , etc sections is the fact that the local angle of attack changes, increasing towards the tip, due to the interaction (Biot Savard) with the opposite wing. There is some, but NOT significant cross flow at cruising conditions, low lift coefficients, when the forward pressure distribution is flat. Go and measure it in a wind tunnel, low turbulence one, where with thin oil the transition can be observed. 3 dimensional CFD designs permit spanwise constant pressure wings to be designed so that the crossflow inside the boundary layer can be almost eliminated. Outside the crossflow happens ONLY with separated flow. Not a cruise condition. Only in viscous flow does the pressure influence the cross flow, never in potential flow. where pressure is determined by energy conservation, in incompressible flow called the bernoulli equation.
@llahneb10 Жыл бұрын
Your videos are information rich, accessible to the non-aerospace engineer, and generally top-tier. I find myself pausing, getting screenshots, and replaying more portions of your videos than any others I see on KZbin. Thanks for the excellent content - the type of content that changes KZbin from a distracting time-suck to a genuinely enriching experience
@ElectricAviation Жыл бұрын
Great to hear!
@hg2. Жыл бұрын
👍👌
@dickmick5517 Жыл бұрын
I hope you got the screen shot of the Mustang that was really a Zero? OPPS
@foxlies010611 ай бұрын
@@dickmick5517 actually I don't think it is a Zero...2-seater... is it a British B-24 Blackburn Skua dive bomber? or a British T-6 trainer?
@RWBHere7 ай бұрын
And most of his information is wrong, Ben @llahneb
@oxcart4172 Жыл бұрын
The Liberator was the B-24 (not the B-54) and the P-51 flew less than a year after the B-24 (not over a decade later!)
@emmanuelgoldstein1918 Жыл бұрын
He can't play it fast and loose with Airplane or Car guys. We know the difference ;)
@GuyIncognito764 Жыл бұрын
Way better explained than when I studied this stuff 20 years ago at uni. Well done!
@michaelngan99 Жыл бұрын
I bet your Prof. throw in a tons of math to make sure you won't get the idea.
@danharold3087 Жыл бұрын
Anyone designing a modern efficient plane needs to address laminar flow at some level. Both the 787-8 and 787-9 employ natural laminar flow on the engine nacelles. Hybrid laminar flow on 787-9 and the 787-10. It also will be used on the two 777X models. I think this is on the tail surfaces.
@wstavis3135 Жыл бұрын
If you have not had the pleasure to fly on a 787 I highly suggest to board one. Really an amazing passenger aircraft, and the "business" class (1st class) is stellar!
@ajs9688 Жыл бұрын
Also, the 737 max winglets are designed for laminar flow
@glennchartrand5411 Жыл бұрын
There is a size limitation to laminar flow. So while certain surfaces/components on an airliner can have laminar airflow , the aircraft fuselage cant.
@hajiosama9352 Жыл бұрын
Am the designer of Honda and Boeing 737 curvy wings , but since 2013 am sitting off surface
@MrCoffis Жыл бұрын
@@ajs9688 how so?
@FredPauling Жыл бұрын
The Celera drag reduction vs standard designs is amazing. It's a shame for Celera that it doesn't scale up, although it would probably look like an airborne Blue Whale. Thanks for rounding out the video on an optimistic note with the promise of similarly efficient designs like the double bubble. I love flying and it would be great to make it much more sustainable.
@ElectricAviation Жыл бұрын
Totally agree
@johndavidwolf4239 Жыл бұрын
If the limiting factor for scaling up the Celera is Reynold's number, why not just decrease its speed, with an increase in size?
@ElectricAviation Жыл бұрын
@@johndavidwolf4239 Yes true. We have got used to flying at 400 mph or more. Problem is the slower moving aircrafts of upto 200 mph, would not find traction with business community and this aircraft is pitched towards them
@nekononiaow Жыл бұрын
@@ElectricAviation Yes but it would make sense for freighter planes.
@z_actual Жыл бұрын
The B-24 Liberator was able to fill the air gap over the Atlantic, leaving U-Boats nowhere to hide. Its long range was made possible by its high aspect ratio laminar flow wing, known as the Davis wing. By the same token, the P-51 Mustang would be able to escort bombers all the way to Germany and back due to its extended range made possible by its laminar flow wing. This despite the Supermarine Spitfire Mk IX of similar size being equipped in some cases with an identical Rolls Royce Merlin engine
@malcolmmckinlay2143 Жыл бұрын
Your information is correct, the B24 was a great success in the war and indeed after in to the 1950s.The Mustang was the most successful fighter plane in the 2nd WW as long as it had the RR engins which replaced the Allisons
@phil4826 Жыл бұрын
Drop tanks helped a lot too.
@XPLAlN Жыл бұрын
The wing of the Spitfire was very efficient aerodynamically, being eliptical which reduces induced drag. However, being a thin wing it was not good for wing tanks (only a few examples had small wing tanks). By Comparison, the P51 could carry a lot of fuel from the get go. This more than anything else accounted for the difference in range performance. I am not saying the P51 wasn't more efficient overall than the Spitfire. According to the late Lee Atwood (of North American) it enjoyed a significant advantage in cooling drag alone. What I am saying is the laminar flow wing is probably the least of it, considering the Spitfire wing was also notable for its inherently efficient eliptical planform, and most of the range advantage was due to the P51 carrying nearly 3 times the internal fuel of most Spits.
@TheDustyShredder Жыл бұрын
@@XPLAlN Let's not forget the combat performance as well. While also reducing drag, laminar flow over the wing results in lower stall speed or higher stall angles. As a result, even with square edge wings, the P-51-D3 when fitted with the Rolls Royce engines could turn fight just as well as a Spitfire. The more powerful and efficient engine in tandem with the laminar flow benefits meant that it could accelerate faster out of a turn, hold more energy through the turn, and enter the turn at higher angles without stalling than it's predecessors. This meant that it outclassed the BF-109s and FW-190s that were still being used as supplements to the Me-262, and was even on par with the overall performance of the Me-262, not counting maximum speed and altitude. And that's not all. The P-36 Hawk also benefited from laminar flow over the wings because the wing design swept forward at the trailing edge, helping to push that cross flow under the fuselage where it could give the plane more tail authority. While the flat nose and cooling flaps on the cowl required for the radial engine certainly doesn't help efficiency, overall drag, or top speed, this plane outperformed many aircraft from it's time simply because of it's wing design, short fuselage, and ability to outmaneuver all of the faster, sleeker designs of the time. In addition, because of the wing design pushing more air to the root of the wing rather than the edges, it had a much higher DNE speed than similar planes with straight wings, but suffered from compression dives far more.
@sheldonholy5047 Жыл бұрын
@@TheDustyShredder you're forgetting the biggest breakthrough of the Mustang, which was reduction in cooling drag versus it's contemporaries
@davidkleinthefamousp Жыл бұрын
Ty for a lovely visit. You answered every unexplained term right away. Yes it’s a B 24, and there was one more word I didn’t get near the end but of course I can’t tell you what it is because I didn’t get it! All in all very well done.
@jasperzanjani Жыл бұрын
this is an amazing synopsis into an aeronautical engineering principle that I had absolutely no clue about. Thank you for sharing your knowledge!
@ElectricAviation Жыл бұрын
Glad it was helpful!
@michaelngan99 Жыл бұрын
"this is an amazing synopsis into an aeronautical engineering principle that I had absolutely no clue about. " It was intentional, to make sure you remain clueless.
@markwadsworth1254 Жыл бұрын
You sound like my subsonic aerodynamics professor! That was a very concise explanation of laminar flow and I agree with you on every point. I think we can adapt our acoustic perforation technology, used on nacelles, for boundary layer control suction but wet wings complicate things. But at least the sonic pressure levels won't be over 160Db!
@ElectricAviation Жыл бұрын
Glad it was helpful!
@larrysorenson47897 ай бұрын
Dad was a USAF TEST OILOT. He once described creating B-47 wings with an internal vacuum and perforated wings. The vacuum was to suck out the disturbed boundary layer.
@santoss.8150 Жыл бұрын
Probably the best part of watching a video that has nothing to do with anything I'm interested in is reading all comments from people fully immersed in the subject matter. So much niche subculture in the world
@anthonycanalese21427 ай бұрын
I would hardly call Aerospace Engineering a "niche subculture".
@jamescole1786 Жыл бұрын
9/18/22. Excellent presentation of 'Laminar Flow' effects on both wing & fuselage of aircraft. Numerous video 'clips' of laboratories testing smoke flow over wing shaped surfaces as the wing is rotated clearly demonstrates the two (2) air 'drag' issues (natural & paracitic) you articulate through this lecture. Absolutely great visuals of aircraft in flight while your voice over explains the history of wing designs, few examples of 'perfect' laminar flow achievement but also newer body designs which reduce drag thus achieving greater fuel efficiency. Related effects of handling characteristics were covered as well. Great video to watch & learn. A+ ! Carry on Sir!👍👍👍😊
@michaelham2366 Жыл бұрын
0Nice video; At 0:58 you call a fighter a P51 Mustang, but that's not a P-51. It may be a Curtiss P-56 Hawk - at any rate, it has a radial engine. Also, just prior to that, you refer to the B-54 Liberator. The Liberator was the B-24.
@ElectricAviation Жыл бұрын
Agree
@robg3545 Жыл бұрын
Its a Commonwealth CA-16 Wirraway
@jtjames79 Жыл бұрын
The biggest reason active laminar flow was never pursued was the maintenance. These days we have handheld rust stripping lasers. It would be a lot easier to do the maintenance these days.
@bbayerit Жыл бұрын
We worked with NASA in the 70s and 80s on Laminar Flow Control panels made for the leading edge (LE) and 70% chord of wings intended to go on commercial a/c. We produced titanium wing panels with 0.0025 diameter, trumpet-shaped holes, 0.010 on center in square and diamond patterns for installation on a testbed a/c. The actual flight test results were outstanding and exceeded calculated expectations. These tests were done using only main wing panels while the program was intended to replace all LE surfaces (nose and vertical and horizontal stabilizers). There was virtually no difference in maintenance from normal paneled surfaces and an added benefit was that the vacuum pumps used for LFC could be reversed for pressure pumping deicing fluid out through the same holes and result in additional savings. The potential issue with insect hits was negligible as the LE was protected by the slats during TO and landing and the deicing fluid could flush debris away. The ultimate limiting factor was the overall cost of replacing existing wings and other surfaces with new versions to the (then) cost of $4M per a/c.
@jtjames79 Жыл бұрын
@@bbayerit That's what I get for trusting the news. Also reinforces my belief that legacy aerospace hasn't been trying for decades.
@PRH123 Жыл бұрын
@@bbayerit interesting, thanks… what were the effects of rain on the flow…? what were the reasons given by manufacturers for new aircraft for not adopting the techniques that you were researching…?
@PRH123 Жыл бұрын
@@jtjames79 hmm, that’s not really fair…. the new technologies that have gone into the 787 for example are pretty amazing…. The outside shape may be quite similar to other jets in production for the precious 50 years, but what it’s made of and what’s inside it are very different…. airlines are very risk averse, for very good reasons, so trying to make a Quantum leap into something like a lifting body is something that they’re not ready to do, it would be in their view almost certain business suicide…
@jtjames79 Жыл бұрын
@@louisvanrijn3964 Reflective paint, or even just a nice bright white. I'm also just saying rust stripping lasers are commercial off the shelf so anything less power than that is also commercial off the shelf. Gunk tends to be dark colored, so it's kind of like laser hair removal. You obviously would want to carefully tune the laser. You could also use a fiber optic laser(s) and carefully target each hole, but you would probably need some sort of robot arm, otherwise a worker is going to be picking up and moving that laser(s) a lot.
@Rovinman Жыл бұрын
When I was at University, some 50 years ago, a friend from the Mechanical Engineering Department, was researching power within laminar flow, by utilising the COANDA Effect. I often wondered since then, what had happened to that idea ?
@everTriumph Жыл бұрын
Don't forget the Kutta-Joukowski theorem!
@michaelngan99 Жыл бұрын
"I often wondered since then, what had happened to that idea ?" It got consigned to the trash can, because it works.
@ManuelGarcia-ww7gj Жыл бұрын
Unexpectedly lucid discussion of the importance of laminar flow in aerodynamics. The Celera has the appearance of a dirigible with wings which made me think that it would never fly, but it appears that it has flown. Clearly, this is an area that needs to be explored by those who are qualified to do so.
@BariumCobaltNitrog3n Жыл бұрын
It looks like a greedy mosquito
@ManuelGarcia-ww7gj Жыл бұрын
@@BariumCobaltNitrog3n It does, doesn't it?
@randyhiggins9635 Жыл бұрын
I worked at Honda Jet in Greensboro .....Contract toolng guy with Pete Payne .....and Larry Tedford years ago .....great info thanks !
@123cp8 Жыл бұрын
You know, sailplanes have been using laminar flow technology since the 1960s. A modern sailplane is among the most efficient, in terms of lift-to-drag, of any aircraft design. Why no mention?
@scottmichael3745 Жыл бұрын
This video was Awesome! :-) Super easy to understand and great visuals! Thanks so much!
@aullvrch Жыл бұрын
That was a super interesting video! I loved to see the modern designs and the evolution of it!
@ElectricAviation Жыл бұрын
Thank you!
@williamforbes5826 Жыл бұрын
Build bigger, thirsty, powerful engines to go fast, or improve efficiency to do it with less. This is true of cars, boats, aeroplanes and even radios! Yup, a great radio is useless without an antenna! Gotta look at the 'whole' package. But every little bit helps. Thanks for the insightful video!
@AdrienLegendre Жыл бұрын
Excellent review. I liked the diagram of the swept wing explaining the purpose of a swept wing.
@markoconnell804 Жыл бұрын
Use of tubercles on the leading edge can also have laminar benefits. Dr. Fish did the research on this.
@herbertshallcross9775 Жыл бұрын
The B-24 and the P-51 were both designed in the early 1940's, not ten years apart.
@stupidburp Жыл бұрын
The Celera 500L looks like a good basis for a long endurance drone aircraft.
@marcv2648 Жыл бұрын
Fantastic presentation on laminar flow control.
@ElectricAviation Жыл бұрын
Glad you liked it!
@EDKFtravels Жыл бұрын
Very well put together. Thanks for a wonderful video!
@ElectricAviation Жыл бұрын
Many thanks!
@martshearer498 Жыл бұрын
I always marvel at the effort applied to make smooth surfaces, when nature's air fleet (bats, birds, months) have fuzzy surfaces.
@ElectricAviation Жыл бұрын
The reason is that nature's way of flying involves capturing energy from vortices. This requires fuzzy surfaces. We cannot achieve that level of complexity at large scale. Hence we rely on mechanically simpler mechanisms of propulsion. This means we fly very differently
@patlevv7382 Жыл бұрын
8OO' per SECOND✈️ N O T realistically attainable. VS. 7O feet per second 🦉
@herbertshallcross9775 Жыл бұрын
Any man carrying aircraft is much larger, and consequently operates at much higher Reynolds numbers than any living flying creature. Even pretty low performance aircraft cannot operate at the slow speed of all but the fastest birds. The flight envelopes are so different that flying must be approached differently.
@CrossWindsPat Жыл бұрын
@@herbertshallcross9775 Yep. Aerodynamics change so drastically at different speeds. I am still shocked at the vertical stabilizer of the X15. You look at that and think it would just be a nightmare in the wind but no, it works.
@ravdeepboparai Жыл бұрын
Look like a real engineer made this video. Very well done
@danielstapler4315 Жыл бұрын
This info is relevant to aircraft that run on batteries as they need to be very efficient.
@justinejacks0n Жыл бұрын
Excellent aeronautical engineering analysis of laminar flow. Interesting and informative. (subscribed)
@ashemgold Жыл бұрын
It always amazes me how a single revelation changes everything forever.
@everTriumph Жыл бұрын
I believe the maths was in place before powered flight.
@darthbuzz1 Жыл бұрын
Thank you for the word 'empennage'. A new one added to my brain.
@denismilic1878 Жыл бұрын
Man, you earned a subscription.
@TERMICOBRA Жыл бұрын
Thank you Sir. I very much appreciate your instincts on the best way to transfer your knowledge to your listener. You know what to say and when to say it to minimize confusion while maximizing absorption.
@ElectricAviation Жыл бұрын
You are very welcome
@Karlengler1 Жыл бұрын
Excellent explanation of laminar flow and how it affects aircraft efficiency, you have made me smarter
@penguinista Жыл бұрын
Great video! This is the kind of content that makes me wonder how big media companies stay in business.
@balloe3466 Жыл бұрын
Very cool video, dense in information yet easy to comprehend. Well done!
@ElectricAviation Жыл бұрын
Glad you liked it!
@patrickmulvany6479 Жыл бұрын
Bravo to the forward thinkers who created the Solara 500L. I wonder what benefit might be derived from ducting the fan?
@dageogaming4478 Жыл бұрын
Ducting a fan causes less induced drag around the tips of the propellor, it also reduces sound. ducted fans often have stator blades that also reuse abit of the energy lost in the circle motion that air behind a fan makes to convert it to backwards motion.
@patrickmulvany6479 Жыл бұрын
@@dageogaming4478 - Realizing those facts, and appreciating all the other ways they optimized the Celera, I was just wondering out loud why they chose not to duct the prop. Wondering about the tradeoffs - weight, drag, disruption of laminar flow?
@dageogaming4478 Жыл бұрын
@@patrickmulvany6479 ducted fans do increase weight and parasitic drag, this drag is a bigger part of the overall drag on higher speeds. I can't tell for sure how it affects laminar flow. ducted fans have their pro's and con's, it's a compromise that has to be made based on what the aircrafts role and flight conditions will be.
@davem5333 Жыл бұрын
What I have wondered about on the Celera is the CG range. How do you balance it full vs. empty?
@myemail5457 Жыл бұрын
Go look at the corrugated steel body of the Ford Trimotor cargo plane from the 1930s it helps,even when it's low tech .
@ianboard544 Жыл бұрын
This was fascinating. Can one look at it like this?: when you have turbulence in the wake of an aircraft, the air is moving, so energy has been transferred from the aircraft to the air. In order for this to happen, work has to be done - this shows up as a drag force. With laminar flow, if perfect, the air behind the aircraft closes up and isn't moving, so less energy has been transferred to the air and so less drag. I would think the Celera won't scale indefinitely because the Reynolds number of the flow goes up with the dimensions so turbulence will happen more easily.
@erictaylor5462 Жыл бұрын
The B-54 was an aircraft purposed by Boeing and was a derivative of the YB-50, itself a derivative of the B-29. It was canceled before the prototype was completed and it never flew. Likely due to the fact it was a piston powered bomber designed in the jet age. The USAF Discovered in Korea that the time of the piston powered bomber had come to an end. The plane hiving its wing blown off is a B-24, probably the best heavy bomber of WWII.
@lubricatedgoat Жыл бұрын
Can this be applied to marine craft? Both surface and submersible?
@ElectricAviation Жыл бұрын
The problem is water is less viscous than air. Yes it might feel the other way around, but air is more sticky. The higher viscosity of air keeps the flow laminar for longer. Water is 10 times less viscous than air, so this unfortunately cannot be applied to marine technology
@lubricatedgoat Жыл бұрын
@@ElectricAviation It certainly does feel the other way around as you said. I was thinking for hydrofoils, and ways to lower friction for moving cargo long distance. Pity about that whole physics thing getting in the way.
@synergyfiles3536 Жыл бұрын
@@lubricatedgoat Actually the viscosity is low but the density is high. The Reynolds number is dependent upon both. It might be possible to apply this on Marine technology
@gpaull2 Жыл бұрын
I had a fiberglass ski boat that got washed up on a rocky shore during a storm. The bottom of the hull was dimpled over the whole surface like a golf ball. It gained several knots of top speed with the damage. Once I got it repaired back to glass smooth it lost the added knots.
@vitordelima Жыл бұрын
It's always active and involves blowing up air around the surfaces in contact with water, hydrophobic surfaces, foils and other complicated tricks.
@rickrasmussen5637 Жыл бұрын
Cars of the future also need to use these breakthroughs! Fuel mileage would increase at the cost of sexy car body styles. God Bless
@danielstapler4315 Жыл бұрын
good concept
@af0ulwind115 Жыл бұрын
Next step... Apply a high voltage plate at the front of the wing or even a material that builds static as the air hits it at high speed and laminate the back half of the wing with a positive charge to attract the negatively charged ions in the air due to the negative at the front of wing
@ryanmcgowan3061 Жыл бұрын
I can see my street at 11:43. I'm always looking up hoping to catch the Celera. My wife saw it, and got excited. She has become an av geek like her husband.
@xoctor Жыл бұрын
Thanks for the brilliantly clear breakdown.
@clarencehopkins7832 Жыл бұрын
Excellent stuff bro
@AnotherCupofTea2 Жыл бұрын
Fascinating, thanks very much 🙂
@samedwardson5911 Жыл бұрын
Bloody well researched & presented- nice one ☝️
@alwayscensored6871 Жыл бұрын
Didn't know about the laminar flow drone. Thanks, will be interesting to apply this to model planes etc.
@ElectricAviation Жыл бұрын
No problem 👍
@arturoeugster7228 Жыл бұрын
12:00 The Reynolds number is proportional to the ratio of the pressure forces to the viscous shear forces ( ½ density × V²× chord × span) ÷ ( viscosity × du/dy × chord×span × [½V÷du/dy × 1/chord] ) = density × V × chord / viscosity = pressure × area / shear stress × area [ ] = factor of proportionality du/dy = boundary layer shear velocity gradient
@swipekonme Жыл бұрын
we need a teflon sleeve with shape shifting to dynamically adapt to air flow. even without shape shifting, we need to have ridges to provide lateral assistance to flow, imagine a flexible system where the ridges raise up and curve based on airflow
@jeremymahrer1832 Жыл бұрын
I love your Indian accent and breadth of knowledge, but you didn't mention Gliders !!!! Thankyou, i loved your video.
@paulodetarsoarrudacorreia6138 Жыл бұрын
VERY GOOD. CONGRATS.
@muumarlin1731 Жыл бұрын
Awesome video - nicely done!
@ElectricAviation Жыл бұрын
Thank you very much!
@JonS Жыл бұрын
Maybe you can create a video explaining how the tooth-like denticles on shark's skin reduce drag? I see there's some research in to applying the same techniques to aircraft wings. Tabulators are already used to reduce lamination separation bubbles, but these don't seem to be the same as dentricles, as sharks have them all over their bodies (I believe), and not just in front of where the laminar separation region would be.
@ElectricAviation Жыл бұрын
That reduces that profile drag. It similar to golf ball indentations. It doesnt reduce the skin drag
@Oneshot8242 Жыл бұрын
Sharknado helps explain a lot of things.
@CrossWindsPat Жыл бұрын
Interesting but I imagine trying to produce such complex shapes over the area of an aircraft would be unimaginably expensive.
@everTriumph Жыл бұрын
inducing very local vortices can re-energise the air flow in the boundary layer, keeping the overall flow attached. You can see this in small 'tabs' on the upper wing of aircraft giving lower stall speeds and better behaviour at the stall. You sometimes see them on performance cars.
@derherrdirektor9686 Жыл бұрын
Top class education. Loved every bit of it.
@oldporkchops Жыл бұрын
I watched your other Otto Celera 500L video too. Both are succinct, technical, yet accessible to non-AV geeks. Thank you for creating videos that a layperson can understand. Otto's press release website has not had an update since 2021. Have you heard any news about the plane?
@dopeymark Жыл бұрын
Thanks, I learned something.
@yahyakhan9745 Жыл бұрын
Amazing information, I am not an aerospace engineer, but very nice information, thank you!
@ElectricAviation Жыл бұрын
Glad you enjoyed it!
@DavidRLentz Жыл бұрын
I have had a nearly lifelong fascination with aircraft! This despite the fact that I cannot see well enough to drive. I also am poor at maths. For this, scientific articles such as yours often elude me in the details. I found your explication so remarkable--thorough, yet accessible--that I finished it. I even reviewed portions to enhance my ap- prehension of your erudition of such complexity. Thank you twice!
@louisvanrijn3964 Жыл бұрын
It is simple. A laminar flow has say 1/5 to 1/7 of the drag compared to a turbulent boundary layer. So: be laminar as far as possible is the goal. Laminar boundary layers a sensative: wobbles in the surface, small dents, specs, bugs, rivet heads, rain; cause transition to a turbulent boudary layer. So you aircraft has to be, and stay in a mint condition. Can that be realised?
@BariumCobaltNitrog3n Жыл бұрын
@@louisvanrijn3964 I'm sorry but if you try to educate someone who has a really good grasp on a concept, you should read what you wrote. Boudary layers a sensative on you aircraft. One is a typo, but ignoring the red lines under words is a bit...wild punctuation, you animal!
@soronir3526 Жыл бұрын
R Kelly made great strides in laminar flow research.
@matthewhayward1843 Жыл бұрын
Excellent video. Really great content and well explained!
@Eugensdiet Жыл бұрын
Good video but I kind of laughed when you mention the B-24 since it has four huge egg beaters totally disrupting the air flow. Perhaps they got good numbers in a wind tunnel but not in real life. Where can I find out more about the relationship of Reynolds number to Laminar flow? How does the coefficient of lift of the NACA 671015 compare to say an Eppler 205? What about using the vacuum holes as a means of extending pins into the airstream to improve the lift coefficient during slow speed operation. The pins would make the air more dynamic. My concern with Laminar flow is the increased risk of lift failure during icing.
@CrossWindsPat Жыл бұрын
Haha this is so true.
@airfoilsinmotion4777 Жыл бұрын
Thank you Sir for a fine video! Having worked in the Aerospace Industry for 30 years (retired) any content with an airplane gets a look. Your presentation contained just enough “science” to be interesting while moving along at a comfortable pace. Are you in academia?
@ElectricAviation Жыл бұрын
I was once a lecturer in Scotland
@audiblevideo Жыл бұрын
how much of laminar flow is used in marine vehicles? Does anyone study fish? The reason I ask is the medium of water has considerably more resistance than water. (I'm not quite sure if that impedes or enhances laminar flow) I any case what do you think the effect of using shark skin like texture (which is like narrow spines or teeth) would have on flow?
@CrossWindsPat Жыл бұрын
Im sure the shark skin would be effective but also unimaginably expensive and complex. Also modern, high speed boats use an ingenious trick where they put a step in the hull (stepped hull) that forces air under the boat, so its a lot less friction because as you said, water is much thicker than air.
@ted_van_loon Жыл бұрын
you forgot one of the most important things, almost 10 years ago NASA pubished a project where they did manage to really prevent turbulence. the last plane you showed in this video seems to kind of use it. and that design solves almost all those problems automatically. the base principle is to not use a static airfoil but instead use a airfoil which transitions from extreme to zero or flat this manages to prevent that turbulence an actually convert it into foreward force(efficiency, so less force needed to move it) and lift(more lift from it as well). it also makes the wings silent and allows them to move at almost any speed without stalling or such, so they can go insanely slow and insanely fast and are stable in flight and autostabilizing. these are around 80% more efficient acording to nasa's numbers. it has also been used in propellors and high speed propellors, which resulted in propellors which didn't make any sound other than the sound of the motor, and where normal propellors eventually begin to lose power at higher speeds untill they really generate no or almost no foreward thrust these propellors kept going efficient even at high speeds and while staying silent(turbulence is what causes the sound in propellors). this technology is quite old however yet still barely used, the only comercial plane using it which I know of is the archeotypzyx(or something like that it was named), however the mars glider(nasa) uses the same wing principle. and for around 10 years some hobby plane/glider builders have used it, most of them being chinese people living in usa out of my findings(since I only saw it discussed on some very speciffic forums which mostly only have such people on them, well and on nasa's site. however while in general it is said that NASA designed those wings/invented it that is not completely true since that wing design actually dates back to almost the beginning of aircrafts, not long after otto lilithan(or such was the name roughly). in germany many hobbyists started building their own small glider planes in their garage to fly with it, that is kind of the beginning of drachenfliegen/hanggliders. back then you couldn't buy them in general, you just build your own one and could just directly fly with it, no legal trouble at all. qutie early on there where a few popular base designs, one of them was quite much like the now famous one(which also accidentally due to things they did to save cost uses that same principle to become more efficient and stable), then there where those more like a plane, but also a few iconic ones back then which where like a plane but had no or little tail and still flew stable and well. those used that same principle to fly and be stable, back then most likely it was largely accidental, but they must have noticed the effects since eventually someone figured out that by doing that it could make it so efficient and stable that it trusted it's life into it and decided to spend that much time to build it rather than building a well used design(well used design doesn't refference to a actual design but more like information they heard from people). so whoever was the first one to build and design/come up with that idea was most likely the actual inventor, however since those where all hobbyists, and industry didn't care about stability or efficiency, it somehow got kind of lost as in that it took many, many years before people realized again that that worked well. for hanggliders, the famous design now used accidentally uses a slightly similar principle to stay stable and be efficient, it isn't really optimized for it, and the real reason that design is used a lot now is because they are super simple to make, maintain, transport(can easily fold them and unfold them), and they are easy to make with little big chances for mistakes etc.
@nickcook3948 Жыл бұрын
Excellent video - thank you!
@sharmapd1 Жыл бұрын
Excellent information provided. Thanks..
@johnconnor3849 Жыл бұрын
Alright…so, what if you direct a portion of your exhaust to slot cut across the top of the wing, behind the maximum thickness, facing the trailing edge, kinda like a blade-less fan. The slot would distribute exhaust evenly across the wing creating an “artificial” boundary layer of laminar flow. Obviously the reason the flow becomes turbulent behind the maximum thickness is because of the vacuum created, so eliminate the vacuum?
@ElectricAviation Жыл бұрын
There is a method where you let compressed air out from the wing surface to energize the boundary layer. What you are talking about is something similar
@CrossWindsPat Жыл бұрын
I wonder if the heat would cause adverse effects though. Remember he said cooling the surface can increase laminar flow. There are many prototypes that use the exhaust gases over the wig to generate more lift at low speeds though.
@everTriumph Жыл бұрын
See Blackburn Buccaneer.
@pauloneill9880 Жыл бұрын
Aliens have designed the tic tac uap with a perfect laminar flow shape.
@TheMilkywayboy Жыл бұрын
What if we make more Celera 500L and make them fly in a V formation like a group of travelling geese.
@CrossWindsPat Жыл бұрын
Efficiency maximized!
@Wolfgang-the-Gray Жыл бұрын
The Liberator bomber was the B-24, not the B-54. The B-54 Ultrafortress was cancelled in 1949 with no flyable examples produced. Also, the plane you show when announcing the P-51 clearly not the Mustang.
@DavidRLentz Жыл бұрын
Was the B-54 from Boeing or Convair?
@XRP747E Жыл бұрын
Excellent video.
@ElectricAviation Жыл бұрын
Thank you very much!
@russelldesilva1560 Жыл бұрын
Really succinct and clearly told. Thank you!
@ElectricAviation Жыл бұрын
Glad it was helpful!
@davidrapalyea7727 Жыл бұрын
Excellent presentation!
@ElectricAviation Жыл бұрын
Thank you kindly!
@howardsimpson489 Жыл бұрын
I always wondered why so little attention was paid to the shape, finish and protuberances on aircraft bodies. It is not just the drag from the lump but also from the trailing turbulence.
@DennisKwasnycia Жыл бұрын
Excellent presentation. Keep up the good work!
@ElectricAviation Жыл бұрын
Thanks, will do!
@justayoutuber1906 Жыл бұрын
I learned something today.
@billsmith5166 Жыл бұрын
Fascinating. The Celera would seem to be a design that would only be laminar in a fairly small envelope of flying conditions based on what would appear to be a propensity for nose-down attitude depending on a fairly tight 50/50 weight distribution that could shift pretty dramatically in a headwind or tailwind situation - among others. Do you know if that's the case. Are the two scoops at the rear top of the empennage used to actively control flow in addition to supplying air for the engine?
@user-xo2yo6jl3o Жыл бұрын
Are there any problems with the location of the propeller? Propellers like "clean" air too, and the wake of the fuselage is definitely not clean. Is that one reason the Beech Starship and the Avanti are so noisy? Great video, though.
@lauriejones3198 Жыл бұрын
Correct. You will notice ALL pusher prop aircraft are noisy because, even if airflow along fuselage is smooth, the prop inevitably passes from high pressure region to low pressure as it rotates. And this alone makes for noise pulses. The prop would have to be either fully above or below the wing which has obvious other issues. My bet, aside from it going nowhere, is that this aircraft will have CG problems, payload deficiency, unsafe pilot visibility, very high takeoff and landing speeds and be deadly in icing conditions. Laminar flow is a nice idea. A wish.
@anthonyxuereb792 Жыл бұрын
Very informative, thank you. What of the "Coke bottle" shape on fuselage design?
@giovannip.1433 Жыл бұрын
What is the sound barrier in denser air? How do we increase the density of air whilst creating lift and then slow down air when the density is reduced?...
@cementeagle3596 Жыл бұрын
the piaggio p-180 turbo prop has a very similar fuselage ,laminer ,tapered design . it is the fastest production passenger turbo prop ...
@samsharp8539 Жыл бұрын
This article proves what doctors have known for almost a century. The suppository is the most aerodynamic design with regards to drag reduction. This fact, as experienced by test pilots, has led them to threaten to rip the wings off of some of these beasts, and stick the rest of the aircraft up the engineer’s…
@ElectricAviation Жыл бұрын
haha
@jamesbanq3660 Жыл бұрын
👏. Well done….well researched documentary
@stephenharlan4126 Жыл бұрын
The Liberator was the B24 not a B54 which by the way is a number that never was used…
@christianhohrhan5723 Жыл бұрын
Excellent informations for me as a non expert
@666toysoldier Жыл бұрын
I believe the Lockheed constellation was the last passenger aircraft with a tapered fuselage. A cylindrical fuselage is easier and cheaper to build, as well as lengthen or shorten for various models.
@marsmotion Жыл бұрын
amazingly educational. wow. good job.
@clavo3352 Жыл бұрын
Amazingly well produced video! Very important topic relative to fuel economy and air pollution. Even battery powered aircraft would greatly benefit from tis technological insight. One wonder whether Canadian geese should be studied! Obviously the X-35 project looked at whales and dolphins.
@xqqqme Жыл бұрын
It's Canada Geese....and only Canada Geese. Not Canadian.
@clavo3352 Жыл бұрын
@@xqqqme Is that Canadian English or Canada English? LOL! Ok okaay Canada Geese. But suppose you made a gravy from the drippings of a baked Canada Geese; wouldn't that be a Canadian Grease gravy?
@CrossWindsPat Жыл бұрын
Studying nature can always teach us, but nothing natural is moving anywhere close to the speeds of even the slowest air crafts, so the point is kinda moot.
@smatthewsauthor Жыл бұрын
11:39 You will notice the common pattern between these successful cases you showed... They all have Phi measurements / geometry. .618 is the size and location of curve changes as well as the laminar hole size 08:50 0.065 (pretty close to .0618). The key between all of these successes is Phi. The same thing applies to vortex coils kzbin.info/www/bejne/qJ7Mc6qohrqapa8 501 a - The Perfect Vortex Coil (Mathematically and Geometrically) - 5 of 6
@LesCish Жыл бұрын
Phi is a ratio, not a unit of measurement. I can't say about the others but certainly cannot be applied to hole diameter (think of whether your comparison would hold if inches, cubits or light-years were used). If it has units, Phi doesn't apply.
@smatthewsauthor Жыл бұрын
@@LesCish Good point with the hole but it applies to everything else. Ironic that the hole size was similar too.
@LesCish Жыл бұрын
@@smatthewsauthor 1. It's not ironic, it's coincidence. Attempting to assign meaning to such coincidences amounts to numerology. 2. Phi "measurements", including size and location is nonsensical as size and locations cannot be specified by a ratio- which by definition has no units. 3. Did I miss something in the video that discusses "curve changes"? What do you mean? 4. Are you sure you aen't suffering from apophenia?
@smatthewsauthor Жыл бұрын
@@LesCish I suffer from the opposite of apophenia. I have 99% pattern recognition aptitude.
@LesCish Жыл бұрын
@@smatthewsauthor Responding only to my 4th question suggests you think this is about you, rather than the facts.
@drdoolittle5724 Жыл бұрын
Thank you for your production, excellent! One more thing please, all my life I have learnt that a prop at the nose encounters no foul air whereas a prop at the rear is doomed, so why do Rutan and the Celera achieve such good figures or would they be even better again with a nose prop?
@ElectricAviation Жыл бұрын
Its true that if the prop is at the rear and doesnt receive clean air, than it makes at noise and also adds to the dynamic loading on the prop itself. It is however, aerodynamically more efficient over all as the wings and fuselage receive clean air
@johndavidwolf4239 Жыл бұрын
@@ElectricAviation : Additionally with a prop at the rear, the wing and fuselage do not see the localized higher air speed of the prop wash nor the turbulence induced by the prop.
@derherrdirektor9686 Жыл бұрын
@@ElectricAviation I believe it is due to the fact that the air comes in laminar. If they achieve their goal, and there is little to no turbulence at the back, it may make no difference to the prop.
@davehayes8812 Жыл бұрын
Thanks! You are a great teacher of these concepts
@JustinSolms Жыл бұрын
So well explained - thank you.
@ElectricAviation Жыл бұрын
Glad it was helpful!
@sergeigen1 Жыл бұрын
super nice video, very well explained, subscribed!
@tdawg332 Жыл бұрын
is there any sort of ground-effect interaction that could destabilize the plane during landing?
@1ntwndrboy198 Жыл бұрын
This is the same way and Al does it to keep its flight at zero decibels just about