Twodimensional ChebyshevFourier DNS software
Hi,
I'm currently writing my first DNScode (FORTRAN or C++) and would appreciate an example of a code to gain insight from. I would like to develope a Chebyshev  Fourier pseudo spectral method to solve incompressible NavierStokes in a square or circular domain. Also I intend to use solid boundary conditions! Any example code or advise would be appreciated. Thanks in advance! Andy. 
Re: Twodimensional ChebyshevFourier DNS software
Hi Andy, I can give you a bunch of references on the code that I have been working on for a while and if you like it I can even give you more details on the coding itself. I have used the Chebyshev expansion in the radial direction and the Fourier series in the (periodic) angular direction. Boundary conditions were reflective at the inner boundary and nonreflective at the outer one, but of course there is no problem to implement all that the way you want. THe main paper on that in the Astrophysical litterature: Godon, 1997, The Astrophysical Journal, vol.480, p.329. (if you are at the University of Cambridge there should be no problem to have access to the library of astrophysics). You can have a look there at the 2D code written for a compressible rotating disc. The Chebyshev method is implemented using a method described by TalEzer and Kossloff (1993). Viscousity, filters, external forces are also introduced. Have a look there and tell me what you think. That's a good start. Otherwise I can give you other references for the same kind of hybrid FourierChebyshev solver. So let me know if that's about the kind of code you are looking for and I'll give you more details. Cheers, Patrick.

Channel Flow DNS help request
I have just seen some of the related posts. I dont know if you are still interested in the FourierChebyshev topic, but at the moment I am trying to code the same via Matlab.
So far I only have 2d case with three different impementation methods. 1 staggered grid [Canuto2007] 2 Coupled [Canuto2007] 3 Splitting method [R.PeyretSpectral methods for incomp vis flow.]  with these codes, Couette and Poiseuille flows seem to be working fine. I have two main questions for you; 1First of all those two cases are fully developed to validate confidently do you have any other suggestion test cases, where solutions are known. There might be many but I would assume, only few would be ok for the periodic B.C. 2I am pretty confused by stepping up to 3d. I might need some help if you would. so if you email me back as an answer, I could give you more detailed explanation of the points I get stuck. emre137@gmail.com Thanks in advance \Emre 
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