Known aerodynamicists? (4 Viewers)

[bf109xxl]

The equations are not a constant they are based on what is known about what is available, but material science is evolving too.

1. Please indicate which equations of theoretical aerodynamics (more precisely, fluid dynamics) have been refuted over time? The physical and mathematical basis is mostly just being extended. Yes, the empirical approach is still very common - not everything can be simulated, wind tunnel experiments are extremely important. But very often a calculation is sufficient for an accurate estimation of the parameters of a phenomenon.
2. Materials science is poorly related to aerodynamics; in this thread we only consider the contribution of the latter.

If you gave all the plans for an F35 to Wilbur and Orville Wright in 1903 they would be impressed but they couldnt build one, and probably couldnt get one built in their lifetimes.

How long would it take to develop the F-35 using a purely empirical approach for aerodynamic optimization nowadays?

 

[pbehn]

1. Please indicate which equations of theoretical aerodynamics (more precisely, fluid dynamics) have been refuted over time? The physical and mathematical basis is mostly just being extended. Yes, the empirical approach is still very common - not everything can be simulated, wind tunnel experiments are extremely important. But very often a calculation is sufficient for an accurate estimation of the parameters of a phenomenon.
2. Materials science is poorly related to aerodynamics; in this thread we only consider the contribution of the latter.

How long would it take to develop the F-35 using a purely empirical approach for aerodynamic optimization nowadays?

Really? If that were true, how do you know the weight of the aircraft or the strength of its wings and spars to know it could perform a 9G turn? Concorde famously changed in length when flying supersonic, such that the pilots on some last flights put their cap in a gap next to a bulkhead that isnt there when the plane is parked, without knowing the strength and elongation under load how do you allow for that in the design?

 

[bf109xxl]

Really? If that were true, how do you know the weight of the aircraft or the strength of its wings and spars to know it could perform a 9G turn?

Really. None of the above has anything to do with aerodynamics (fluid mechanics). It's either dynamics (pure mechanics) or mechanics of materials.

 

[bf109xxl]

From Wiki:

Aerodynamics ... is the study of the motion of air, particularly when affected by a solid object, such as an airplane wing.[1] It involves topics covered in the field of fluid dynamics and its subfield of gas dynamics, and is an important domain of study in aeronautics.

 

[Sabrejet]

Not sure what this thread is about really; a few examples have been cited, yet discussion veers off every time it gets to specific individuals.

 

[bf109xxl]

Not sure what this thread is about really; a few examples have been cited, yet discussion veers off every time it gets to specific individuals.

The discussion is more around the definition of " aerodynamicist". For some people - including me - it is a physicist, a researcher who develops a scientific explanation of a phenomenon. For others, it is an engineer responsible for optimizing the aerodynamic properties of an object (aircraft, blower, etc.) using ready-made approaches developed by researchers.

 

[ThomasP]

Because of the time we are considering, when designers often had to wear two (or more) hats, I consider many of the designers to be handling a combination of the two fields - physics and engineering (ie theory and application).

 

[pbehn]

Really. None of the above has anything to do with aerodynamics (fluid mechanics). It's either dynamics (pure mechanics) or mechanics of materials.

Thanks, so aerodynamics is nothing to do with designing aircraft, glad we sorted that one out.

 

[Sabrejet]

Well I'm confused. Aerodynamics. Aerodynamicists. Or was this just an excuse for an argument?

George Scharier at Boeing. Any discussion on this?

 

[ThomasP]

He would be a good example of what I was saying, in that he operated in multiple disciplines, though his degrees were in engineering and not physics/aerodynamics.

 

[bf109xxl]

Thanks, so aerodynamics is nothing to do with designing aircraft, glad we sorted that one out.

Erroneous logic. Aerodynamics (equations, methods) is used to design airplanes, but does not mean design itself. Simply check out a textbook on aerodynamics (fluid mechanics).

 

[pbehn]

Erroneous logic. Aerodynamics (equations, methods) is used to design airplanes, but does not mean design itself. Simply check out a textbook on aerodynamics (fluid mechanics).

Thanks for that clarification, now please clarify what an aerodynamicist does?

 

[bf109xxl]

Thanks for that clarification, now please clarify what an aerodynamicist does?

An aerodynamicist deals with the description of the phenomena arising in moving fluids as well as during the motion of a body through a fluid. He predicts in particular pressure, temperature and velocity distributions in a fluid as well as forces and moments generated on a body moving through a fluid. "Prediction" means, here, the development of computational methods that can be described by mathematical equations. Aerodynamics textbooks for engineers often include a section on flight mechanics, which is not a section of aerodynamics but utilizes methods of applied aerodynamics.

 

[bf109xxl]

Known aerodynamicists (researchers): Nikolay Zhukovsky (a founder of the modern aerodynamics), Ludwig Prandtl, Theodore von Karman, Adolf Buseman, Sergey Chaplygin, Hans Liepmann, Hermann Glauert, Mstislav Keldysh, ...

 

[don4331]

Aren't Stanley Hooker's degrees in Mathematics, Hydrodynamics and Aeronautics (not Engineering) - hence the quip, "Not much of an engineer". His initial contribution is the formula for airflow being used was wrong, and by correction of the formula, RR was then able to apply it to improve the intake and supercharger efficiency. Now being able to apply the theory to practical solution makes it useful - which make Mr. Hooker truly great, IMHO.

The Wrights, Beverley Shenstone, Kelly Johnson, etc are applied aerodynamicists aka engineers.

Sidney Camm was applied aerodynamicist - he took the data from the RAE wind tunnel and applied it to the design of his aircraft. Which is why when the data was wrong for high speed (low transonic), his fighters - Hurricane and more so Typhoon had performance limitations.

 

[pbehn]

Known aerodynamicists (researchers): Nikolay Zhukovsky (a founder of the modern aerodynamics), Ludwig Prandtl, Theodore von Karman, Adolf Buseman, Sergey Chaplygin, Hans Liepmann, Hermann Glauert, Mstislav Keldysh, ...

I didnt ask for names I asked what they did, if not researching the theoretical answers to real world issues?

 

[bf109xxl]

Stanley Hooker...
The Wrights, Beverley Shenstone, Kelly Johnson, etc are applied aerodynamicists aka engineers.

Ok, I agree, "applied aerodynamicists", however "not much of an engineer".

Sidney Camm was applied aerodynamicist - he took the data from the RAE wind tunnel and applied it to the design of his aircraft.

He just followed the advice on thickness-chord ratio without critical analysis of the experimental conditions. However, critical analysis of the wind tunnel experiment was (probably still is) extremely difficult, so Camm simply lacked intuition.

 

[bf109xxl]

I didnt ask for names I asked what they did, if not researching the theoretical answers to real world issues?

1. That wasn't an answer to you. I just listed the most important researchers in the field of theoretical aerodynamics.
2. Without exception, all theorists - even pure mathematicians - are engaged in the study of what is supposed to answer to "real world issues".

 

[pbehn]

1. That wasn't an answer to you. I just listed the most important researchers in the field of theoretical aerodynamics.
2. Without exception, all theorists - even pure mathematicians - are engaged in the study of what is supposed to answer to "real world issues".

Exactly, even when I was studying pure and applied mathematics I was given real wold examples and problems to solve. Discussing structures the size of the moon or ones made from materials of infinite strength and zero weight is a pointless activity.

Ok, I agree, "applied aerodynamicists", however "not much of an engineer".

He just followed the advice on thickness-chord ratio without critical analysis of the experimental conditions. However, critical analysis of the wind tunnel experiment was (probably still is) extremely difficult, so Camm simply lacked intuition.

Tell me that the advice wasnt based on something in theory that turned out to be wrong? The laws are cast in stone and irrefutable arent they? Or is it like every other science, the rules are right until proved wrong by another rule?

 

[bf109xxl]

Discussing structures the size of the moon or ones made from materials of infinite strength and zero weight is a pointless activity.

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.

Tell me that the advice wasnt based on something in theory that turned out to be wrong?

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.

The laws are cast in stone and irrefutable arent they? Or is it like every other science, the rules are right until proved wrong by another rule?

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