Hi all,

I would like to know what kind of scheme is used in Fluent for compressible flow (transonic and supersonic flow) simulation. SIMPLE based method ? Roe scheme or Jameson type central difference ?

And what scheme is used for compressible flow in other major commercial codes like CFX, Star-CD ?

Regards

Li

As I know, there are two kinds of solver in Fluent, segregated solver and coupled solver. Usually for compressible flow, coupled solver is used to calculate governing equations. In this type of solver, whole governing equations are calculated simultaneously. So, at least, SIMPLE sheme is not the case in coupled solver. As you know, SIMPLE is a velocity-pressure coupling method.

If you want to know more, go here below and find "coupled solver".

http://calmip.cict.fr:8010/fluent/fluent5/ug/html/i_c.htm

In Fluent Roe Scheme is used for inviscid flux calculation. Initially they were using Jameson scheme later moved to Roe Scheme.

Coming to other solvers, they are mainly pressure based algorithms with corrections for compressibility effects.

If you select "2nd order high resolution" when running compressible flows in CFX-5 it uses an "upwind + second order deferred correction" for convection. The second order correction is limited to keep the behaviour monotonic around regions with large gradients. The limiter is somewhat similar to MUSCL (originally by van Leer, and somewhat modified by Barth/Venkatakrishnan [sp?]). You could also run QUICK, Second Order Upwind, or Central Differencing, but they are obviously not monotone around shocks/contact surfaces.

Dan.