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Old 13th Apr 2013, 10:03
  #16 (permalink)  
Owain Glyndwr
Join Date: Jun 2011
Location: West of Offa's dyke
Age: 84
Posts: 474
I hope in 2013 we have the capability of simulating the unsteady flow around wings, even in the transonic regime. What is lacking is probably just some experimental data to validate the computations
. I'm not so confident. I would think there is quite some iterations between calculation and actual data required to come to a reliable prediction.
I ain't quite that easy! It is (relatively) straightforward to establish the 'static' characteristics (lift, pitch, rolling moment due to sideslip etc.) well beyond the stall using wind tunnel tests - to the best of my knowledge the theoretical methods available still struggle with nonlinear separated flows, but I've been out of the business for a while.

The problem is that to adequately simulate the aircraft's motion one needs to have the 'dynamic' characteristics also (eg rolling moment due to rate of roll etc.) and I certainly don't think CFD will be able to handle that for a while. Some of these are extremely nonlinear in the stall regime and cannot be easily simulated.

For a good description of the problems see AIAA 2005 - 5933.

Obviously there will be research aimed at improving this situation, maybe using dynamic models.

Last edited by Owain Glyndwr; 13th Apr 2013 at 10:07.
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