Known aerodynamicists?

[pbehn]

You just have a limited view of real world issues and don't see all the interrelationships between theory and practice. Any theory operates with abstractions, and sometimes it is extremely useful to consider the limiting cases first.

The advice was based on empirical wind tunnel data, not theory. But the experimental data was flawed because the effect of turbulence was not taken into account.

I have already asked for examples of theoretical aerodynamics equations that have been rejected subsequently.

1 I just have a different view to you.
2 why didnt they use the fundamental laws of fluid dynamics which are true eternal and cast in stone?
3 You have been given the example of Hooker, throw in Whittle and the jet engine which many believed would not work.

 

[bf109xxl]

1 I just have a different view to you.

I kindly asked you to justify your opinion. I'm not interested in "just an opinion". It has no value.

2 why didnt they use the fundamental laws of fluid dynamics which are true eternal and cast in stone?

I asked you about an example.

3 You have been given the example of Hooker

I was actually the one who first gave the example of Hooker. And then I agreed that he could be considered an "applied aerodynamicist". I have read his reports (one even translated into LaTeX - in order to practice the latter) and have an impression of his level.

throw in Whittle and the jet engine which many believed would not work.

The jet engine _theory_ was proposed by Soviet scientist Boris Stechkin in 1929. I have a scan of his article. And matters of belief are not relevant to the topic of the forum.

 

[pinehilljoe]

Orville and Wilbur, and Ludwig Prandtl come to mind as three of the earliest.

 

[pbehn]

I kindly asked you to justify your opinion. I'm not interested in "just an opinion". It has no value.

I asked you about an example.

I was actually the one who first gave the example of Hooker. And then I agreed that he could be considered an "applied aerodynamicist". I have read his reports (one even translated into LaTeX - in order to practice the latter) and have an impression of his level.

The jet engine _theory_ was proposed by Soviet scientist Boris Stechkin in 1929. I have a scan of his article. And matters of belief are not relevant to the topic of the forum.

It is just your view that says you are right, theory without proof in practice is just about worthless, there have been all sorts of madcap theories through the years, look at all the early aircraft designs many never flew and fell apart but were all obviously based on some theory or other.

Its you who said the laws of fluid dynamics are constant. If everything was known then why did designers of accepted designs for large companies produce failures, or designs that needed modification to be safe? Were the problems experienced by the P-47 and P38 in dives solved on a piece of paper or in a wind tunnel? They werent stupid or wanting to kill people they were working in areas not covered by the knowledge of the time.

So the Soviets had a jet engine design in 1929? Or just a theory? Why didnt they build one, or a few thousand and start the jet age before 1941? Why did the Mig 15 start life with reverse engineered BMW engines and then progress to reverse engineered RR Nene engines? After all they had the theory, what was stopping them? There is a simple question for you. Along with your scan of a jet engine theory from 1929 throw in a scan of every other theory produced around the world in 1929 about engines and aircraft.

 

[Sabrejet]

So it was an excuse for an argument.

 

[bf109xxl]

It is just your view that says you are right, theory without proof in practice is just about worthless

The aerodynamic theory is widely used in practice. If any theory still not proved in praxis it doesn't mean it is worthless. There are plenty of examples where theory was created without any practical application that was discovered later. For example, the relativity theory.

there have been all sorts of madcap theories through the years, look at all the early aircraft designs many never flew and fell apart but were all obviously based on some theory or other.

Please give particular examples.

Its you who said the laws of fluid dynamics are constant.

Surely. And you've never once managed to refute that.

If everything was known then why did designers of accepted designs for large companies produce failures, or designs that needed modification to be safe? Were the problems experienced by the P-47 and P38 in dives solved on a piece of paper or in a wind tunnel?

Both.

They werent stupid or wanting to kill people they were working in areas not covered by the knowledge of the time.

The application of theory required computational power which was not available to that time.

So the Soviets had a jet engine design in 1929?

The Soviets have published the theory which helped to estimate the potential of jet engines. The main problem of the Soviets was the lack of heat-resistant materials and insufficient scientific personnel. Lyul'ka was developing a turbojet engine with axial compressor since 1939. By 1948 his engine TR-3 was quite operational (TR-1 was ready in 1945, but was not completed to appropriate reliability).

Or just a theory? Why didnt they build one, or a few thousand and start the jet age before 1941?

Because they were technologically weak. And the theory is not sufficient to build an engine.

Why did the Mig 15 start life with reverse engineered BMW engines and then progress to reverse engineered RR Nene engines?

Mig-15 started already with officially purchased Nene. Mig-9 was equipped with BMW engines. But it true - the Soviets needed Western technology in the production of materials. It has nothing to do with aerodynamics.

After all they had the theory, what was stopping them? There is a simple question for you.

Although the question is completely incorrect, the answer is quite obvious.

 

[Simon Thomas]

John Roncz. One of the greatest, but alas one who will never get the recognition he deserves. He worked on Voyager, Pond Racer, the RV-9 has his aerofoil and plenty more.
After he passed a few month back, I contacted EAA to ask what was being done to celebrate his life. To my surprise they did nothing.

There is a forum at AirVenture about him by one of his collegues.

How to Think Like John Roncz - Details

events.rdmobile.com

I'll be there.

 

[pbehn]

The aerodynamic theory is widely used in practice. If any theory still not proved in praxis it doesn't mean it is worthless. There are plenty of examples where theory was created without any practical application that was discovered later. For example, the relativity theory.

Please give particular examples.

Surely. And you've never once managed to refute that.

Both.

The application of theory required computational power which was not available to that time.

The Soviets have published the theory which helped to estimate the potential of jet engines. The main problem of the Soviets was the lack of heat-resistant materials and insufficient scientific personnel. Lyul'ka was developing a turbojet engine with axial compressor since 1939. By 1948 his engine TR-3 was quite operational (TR-1 was ready in 1945, but was not completed to appropriate reliability).

Because they were technologically weak. And the theory is not sufficient to build an engine.

Mig-15 started already with officially purchased Nene. Mig-9 was equipped with BMW engines. But it true - the Soviets needed Western technology in the production of materials. It has nothing to do with aerodynamics.

Although the question is completely incorrect, the answer is quite obvious.

Are you saying that the theory is great but someone needs to invent a computer to work it all out? If they could have worked out the solution to the P-47 and P-38 on a piece of paper why didnt they before they started crashing? After some crashed people formulated a theory as to why. Why didnt the Soviets build jets? you didnt answer, the fact is having a theory means nothing if you cant make it work, even when they obtained a working jet engine from BMW they didnt devolop that the obtained another the Nene and then developed that, I dont care if they purchased the Nene or stole it, they reverse engineered it, if they didnt they would have just had 2 Mig 15s. You argue that theories are not worthless unless they could be made to work, yet the Soviets had the theory of the jet engine in 1929 (you have the document) but didnt make it work, even when they got one they still wanted another one because the theories are useless without the materials. Here is a video of some early disasters, mostly comical. Add to that the de Havilland 108 Swallow which killed the test pilot and son of the company founder and 2 other test pilots, only 3 were made. The forum wont display it, google "Early aviation disasters"

 

[drgondog]

Aerodynamics is a branch of physics. The designers responsible for aerodynamics are engineers, not scientists. In my opinion, the most important contribution was made by scientists, who gave engineers the computational basis (mathematical equations, etc.). So, even the contributions of very talented engineers who dealt with aerodynamic problems like sir Stanley Hooker (2-stage SC for Merlins) cannot be compared to the solution of extremely complex mathematical and physical problems by researchers.

I certainly disagree the simplistic definition. Aerodynamics, airframe structures, CFD, Flight Mechanics have the common roots of both Physics and Math

The aerospace engineer is broadly grounded in Newtonian physics and advanced mathematics (at least through differential equations, calculus, calculus of variations, complex variables, control and matrix theory). The engineer of the 60s had in his Batchelor degree, the equivalent of PhD in either physics or math of the 40s.

Mathematicians certainly guided relaxation techniques - but engineers applied the techniques to codify the approach with high-speed computers to develop CFD (combined with complex variable sources and sinks and field theory) as well as solutions to Navier-Stokes as well as advanced structural modeling.

The aero engineer shaped advanced theory to practical application. The example of the Mustang airfoil development was a classic case of mapping flow between complex space (Kutta-Jukowski, Theordorsen, Prandtl) and two dimensional coordinates to predict (and re-iteratively re-do) CLmax, CM, Pressure distribution, etc. then modify to desirable aero parameters. Both the physicist and the mathematician easily perform the same calculations - but don't know 'why'.

If your point is to cite intellectually superior problem solving to those with either physics or math degrees - I'd love to hear your logic?

 

[bf109xxl]

Are you saying that the theory is great but someone needs to invent a computer to work it all out? If they could have worked out the solution to the P-47 and P-38 on a piece of paper why didnt they before they started crashing? After some crashed people formulated a theory as to why. Why didnt the Soviets build jets? you didnt answer, the fact is having a theory means nothing if you cant make it work, even when they obtained a working jet engine from BMW they didnt devolop that the obtained another the Nene and then developed that, I dont care if they purchased the Nene or stole it, they reverse engineered it, if they didnt they would have just had 2 Mig 15s. You argue that theories are not worthless unless they could be made to work, yet the Soviets had the theory of the jet engine in 1929 (you have the document) but didnt make it work, even when they got one they still wanted another one because the theories are useless without the materials. Here is a video of some early disasters, mostly comical. Add to that the de Havilland 108 Swallow which killed the test pilot and son of the company founder and 2 other test pilots, only 3 were made. The forum wont display it, google "Early aviation disasters"

You seem to be engaging in demagoguery.
I think you understand perfectly well that no aerodynamic theory will help to create heat-resistant alloys, but still you repeat this nonsense "argument". No aerodynamic theory will help to create metal working machines with the required precision and engine manufacturing technology. But that has no impact on the significance of these theories. Because no material science will help to optimize supersonic (and even more - hypersonic) streamline.
Once the Soviets had access to German and British materials and technology, they very quickly developed some very successful engines that had no western prototypes. By the mid-1950s, the Soviets had their own quite powerful engines, and for a time Soviet jet engines were quite on par with their Western counterparts. The Soviets almost simultaneously with the Americans launched mass production of a supersonic fighter, which in flight performance was superior to the American F-100, and its engines were of original design (Mikulin). The Soviets were much better with theories than with technologies.
If a theory requires a lot of computing power, it does not mean that it is a bad theory. It only means that it describes extremely complex phenomena or objects. For example, for modeling thermophysical devices (e.g., furnaces for the single crystals growth), long-known equations (e.g., Fourier) are used, which work perfectly well, but the complexity of the object does not allow them to be solved in analytical form. Therefore, numerical simulations are used - and only recently (last decade) simulations began to give more or less satisfactory results, namely when it became possible to use computational grids with sufficient density. But no one say that the equations underlying the calculations are somehow bad. I can give many such examples.

 

[bf109xxl]

I certainly disagree the simplistic definition. Aerodynamics, airframe structures, CFD, Flight Mechanics have the common roots of both Physics and Math

Everything has roots of physics and mathematics. Mathematics is a common language of science.

The aerospace engineer is broadly grounded in Newtonian physics and advanced mathematics (at least through differential equations, calculus, calculus of variations, complex variables, control and matrix theory). The engineer of the 60s had in his Batchelor degree, the equivalent of PhD in either physics or math of the 40s.

I already agreed above that I was too focused on theoretical aerodynamics, even though there is a huge range of applied aerodynamics problems. And yes, I find the work of theoretical physicists more challenging because they deal with more complex abstractions. Although theoretical aerodynamicists have always been closer to mathematicians.

PS. I did basic research in the academic sector for a long time and then moved to the industrial research, thus I can compare the challenges.

 

[pbehn]

You seem to be engaging in demagoguery.
I think you understand perfectly well that no aerodynamic theory will help to create heat-resistant alloys, but still you repeat this nonsense "argument". No aerodynamic theory will help to create metal working machines with the required precision and engine manufacturing technology. But that has no impact on the significance of these theories. Because no material science will help to optimize supersonic (and even more - hypersonic) streamline.
Once the Soviets had access to German and British materials and technology, they very quickly developed some very successful engines that had no western prototypes. By the mid-1950s, the Soviets had their own quite powerful engines, and for a time Soviet jet engines were quite on par with their Western counterparts. The Soviets almost simultaneously with the Americans launched mass production of a supersonic fighter, which in flight performance was superior to the American F-100, and its engines were of original design (Mikulin). The Soviets were much better with theories than with technologies.
If a theory requires a lot of computing power, it does not mean that it is a bad theory. It only means that it describes extremely complex phenomena or objects. For example, for modeling thermophysical devices (e.g., furnaces for the single crystals growth), long-known equations (e.g., Fourier) are used, which work perfectly well, but the complexity of the object does not allow them to be solved in analytical form. Therefore, numerical simulations are used - and only recently (last decade) simulations began to give more or less satisfactory results, namely when it became possible to use computational grids with sufficient density. But no one say that the equations underlying the calculations are somehow bad. I can give many such examples.

That is a change of heart, dont distract me I am off to design the next generation of fighter bombers. They will weigh 2 kilos, travel at Mach 5 for 27,000 miles on a gallon of fuel. I will use a mixture of unobtanium and cantbehadium (un-ca) alloys married to my own design of engine unlimited power in 2 square centimeters, it will be a world beater, after all, you dont need to take account of the real world with a theory, do you? As you say no aerodynamic theory will help create heat resistant alloys but without heat resistant alloys your 1929 paper is useless, like my design in un-ca alloy. The alloys that you say were beyond Soviet industry I used to see by the tonne waiting at the liner welding machines in Germany Inconel 625 is used as a liner in oil pipelines for high temperature sour service. Aerodynamics is a science like all other sciences it is constrained by what is known and what can be done, it also has a lot of intellectuals with a lot of pride and reputation invested in their pet theory, which may or may not be correct. If the laws of aerodynamics were true and have always been true why do aeroplanes develop new features, like the upswept tips on civilian airliners? Were previous designers stupid ignorant and incompetent or did the industry learn something about tip vortices that wasnt known before?

 

[bf109xxl]

That is a change of heart, dont distract me I am off to design the next generation of fighter bombers.

So, you have finally decided to replace rational argumentation with flamboyant emotionality. Then I have to say goodbye - I do not intend to continue the discussion in such a tone.

 

[pbehn]

So, you have finally decided to replace rational argumentation with flamboyant emotionality. Then I have to say goodbye - I do not intend to continue the discussion in such a tone.

You are conducting a Monty Python argument, can you tell m if it is for 5 minutes or 10? You, of course are always right, even when you boast of having a 1929 theory for a Soviet for a jet that wasnt built you still maintain that the real world has nothing to do with the purity of thought found only in aerodynamics.

 

[Tom Fey]

Irving Ashkenas did a lot of the ductwork on the P-51 as well as work on the vintage Northrop Flying wings. As for modern times, the late John Roncz had a magnificent brain matched with curiosity and drive that allowed him to achieve greatness in several fields including aerodynamics. Paul B. MacCready was another modern aerodynamic and structural genius.

 

[drgondog]

Irving Ashkenas did a lot of the ductwork on the P-51 as well as work on the vintage Northrop Flying wings. As for modern times, the late John Roncz had a magnificent brain matched with curiosity and drive that allowed him to achieve greatness in several fields including aerodynamics. Paul B. MacCready was another modern aerodynamic and structural genius.

Tom - Ashkenas is credited for being major contributor by Horkey for both help in solving the 'rumble issue' in XP-51B and also in the transformation team creating the High Speed/Low drag airfoil - but he was the team lead primarily focused on thermodynamics - and improvements to reduce cooling drag of 'meredith effect' type designs.

 

[swampyankee]

Aerodynamics are an essential part of aircraft design. While the chief designers often have known names, what about the men who were responsible for aerodynamics. Were there especially talented aerodynamicists, to take an example out of Formula 1, the legendary Adrian Newey who would improve the craft to being serial winners everywhere he went?

Robert Jones
Dietrich Kuchemann
Johanna Weber

 

[Peter Gunn]

I dunno, the only guy I know that slings that lingo (over my head I admit) about aerodynamics, airframe structures, CFD, Flight Mechanics is that drgondog guy

 

[drgondog]

I dunno, the only guy I know that slings that lingo (over my head I admit) about aerodynamics, airframe structures, CFD, Flight Mechanics is that drgondog guy

On this forum, David Lednicer aka aeroweenie has forgotten more than I remember today.

 

[Juha3]

... Why didnt the Soviets build jets? you didnt answer, the fact is having a theory means nothing if you cant make it work, even when they obtained a working jet engine from BMW they didnt devolop that the obtained another the Nene ...

What about MiG-9, went into production soon after WWII, appr. 600 were built, each with two reverse-engineered BMW 003s, namely RD-20s, the jet engine was later developed into RD-20F/RD-21.