<div class="gmail_quote">On Thu, Apr 14, 2011 at 19:20, Denner, Fabian <span dir="ltr"><<a href="mailto:f.denner09@imperial.ac.uk">f.denner09@imperial.ac.uk</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div id=":2v6">I have a question concerning pre-conditioner/solver pairs for CFD. I'm using the BiCGStab solver with a Jacobi pre-conditioner at present to perform parallel simulations of fluid flow on unstructured grids.</div>
</blockquote><div><br></div><div>There are lots of methods for CFD. Maybe you could be more specific about what you're solving (laminar, RANS, LES, DNS; compressible?; fully implicit, v-p split implicit, explicit v/implicit p). The mesh quality is also relevant. Do you have aspect ratio 10^6 elements as for wall-resolved LES?</div>
<div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;"><div id=":2v6"> It works, however, for large meshes (>100k elements) the solver doesn't scale very well in terms of necessary iterations to reach a certain tolerance.<br>
Does anybody have experience on which pre-conditioner works best for parallel CFD simulations using the BiCGStab solver? How is the convergence and stability of the multigrid solver compared to BiCGStab?</div></blockquote>
</div><br><div>1/(\Delta x) iterations versus 1</div>