Talk:Ludwig Prandtl

message: There is a claim in the article that Prandtl may have built the first wind tunnel.  "A History of Aerodynamics" by John D Anderson Jr (CUP) states that the first such, 18 in square and 10 feet long was built by Francis Wenham with a group of three other engineers.  The starting point was a paper by Wenham to the Aeronautical Society of Great Britain (ASGB) in 1866, which led to the formation of a sub committee in 1870; it chose the engineers and provided funding. Exactly when the first data were taken is not given by Anderson, but sometime 1870-2 fits his account.  By 1872 the tunnel had been displayed publicly in London.  There is probably more detail in the Annual Reports of the ASGB (especially 1872), but the whole process seems well recorded and beyond dispute.  It was crude, of course but gave useful info on e.g. lift to drag ratios and forces on inclined plates.  I suggest we remove the claim.TSRL (talk) 19:53, 19 August 2009 (UTC)
thread_title: Wind tunnels

message: Having looked at the header again I'd be inclined to revert to that of 2 June 2009.  A lot of words were added by the next editor, without a great increase of content, though it is true Prandtl had things to say on compressibility.  Reading Anderson, his strengths seem to have been those of the physicist (identifying the important parts of a problem) rather than the ability to get formal solutions to complete equations.  There is a lot of confusion, it seems to me in the current header over his role as mathematician, physicist or engineer.  The header should be more focussed and a reversion, with a nod to compressibility would, I think be better.TSRL (talk) 22:40, 19 August 2009 (UTC)
thread_title: Header

message: I am sure I read somewhere that Prandtl had cooperate for some research and teaching to US Allied and he allowed them to access his research and work.
I believe this should be mentioned in this new paragraph of the Article.  — Preceding unsigned comment added by 168.187.205.102 (talk) 10:09, 16 July 2011 (UTC)
thread_title: Life and Research with the Allied and USA After WWII 

message: Shouldn't there be mentioned that through identifying boundary layers, Prandtl resolved the schism which existed between hydrodynamicians and engineers ?  — Preceding unsigned comment added by 193.157.205.97 (talk) 08:15, 13 June 2013 (UTC)
thread_title:  Reunification of hydraulics and hydrodynamics 

message: Substituted at 22:35, 29 April 2016 (UTC)
thread_title: Assessment comment

message: "Prandtl later extended his theory to describe a bell-like lift distribution,"
My understanding is that he re-evaluated his theory which had resulted in elliptical lift distribution and instead of constraining wing span, as was originally assumed to be the main component of drag for the aircraft much like a car, constrained total lift, which is far more appropriate for an aircraft. He did this by minimizing bending moment of the wing, reasoning that larger bending moment required more structure to support. 
" obtained by washing out the wing tips until negative lift was obtained,"
While the resulting lift equations can be used to determine optimal downwash for an aircraft, Prandtl himself did not understand how to practically achieve this goal. His 1933 paper concluded that the solution is sharp tipped wings, suggesting that he never thought of washout, and instead was thinking of adjusting lift solely with planform. It is impossible to achieve the proper lift distribution with planform alone. To achieve the desired lift distribution, downwash transitions to upwash, but the lift is never negative. Instead the transition has the effect of slightly rotating the lift vector forward towards the tips. 
 
"which gave the minimum induced drag for any given aircraft weight,"
This part is suggested in his 1933 paper
"also suggesting that adverse yaw forces could be countered solely by wing tip aerodynamics,"
This part is not suggested anywhere in his paper. My understanding is that Al Bowers put together 1.) achieving downwash and lift distribution described by Prandtl through a combination of planform and non linear wing twist, 2.) that the rotation of the lift vector forward near the tips could be used to achieve proverse yaw, 3.) that such proverse yaw may eliminate the need for a vertical tail
"but this new theory was largely ignored."
true
"In the 21st century the American engineer Al Bowers has confirmed the idea, calling his experimental wing the PRANDTL-D."
I believe the program itself is called PRANDTL-D, and that there have been 4 aircraft constructed, 1, 2, 3, and 3c, so each wing would have a name such as PRANDTL-D 3c
JKBodylski (talk) 10:54, 15 September 2018 (UTC)
thread_title:  "Later years" contains some assumptions and possible errors 

message: I will be adding information to the third paragraph of Early Years about where Prandtl worked after university and a more specific description of what he did there. Srlg36 (talk) 17:27, 3 March 2023 (UTC)
thread_title:  Prandtl's Work after University 

message: — Assignment last updated by K8shep (talk) 18:02, 12 March 2023 (UTC)
thread_title: Wiki Education assignment: History of Science

message: I am removing the "In 1922, Prandtl together with Richard von Mises..." in the Later Years section and adding information about the GAMM and ZAMM. Srlg36 (talk) 16:01, 14 April 2023 (UTC)
replies: text: I will also be adding information about the professional rivalry between von Kármán and Prandtl in the later years section. I am altering the paragraph that begins with "After discovering the boundary layer..." Srlg36 (talk) 16:34, 14 April 2023 (UTC)
replies: text: I continued with adding further information on Prandtl's work at Göttingen, starting at: "The effect of the paper was so great that Prandtl would succeed..." Srlg36 (talk) 02:40, 28 April 2023 (UTC)
thread_title:  New material in Later Years