Fluent 6.3 first run
 

Hi. I did my first official 6.3 Fluent calculation today. I started out with the old segregated solver on my case and after som 100 iterations i switched to the promising coupled solver, but the result was not as good as expected.

<table style="width:auto;"><tr><td>http://lh5.google.com/image/michaelb...led_solver.jpg</td></tr><tr><td style="font-family:arial,sans-serif; font-size:66%; text-align:right">From fluent6.3</td></tr></table>

Re: Fluent 6.3 first run
 

What is your question.

Convergence was flat before switching to the coupled solver and after

Re: Fluent 6.3 first run
 

Try using the FMG initializer (TUI command: s i fmg y) and skip using the segregated solver, go straight to the coupled one.

Good luck, Jason

Re: Fluent 6.3 first run
 

Careful - the coupled solver does not do well with flow separation.

Re: Fluent 6.3 first run
 

There's limitations to all of the solvers. The pressure based coupled solver still doesn't do as well at supersonic flows as the density based coupled solver, and either of the pressure based solvers do better in the low Mach number regimes compared to the density based solver. The density based coupled solver would choke on separated flows in any flow regime. I haven't gotten an opportunity to try the pressure based coupled solver with separated flows. I thought the main problem with separated flows for the old coupled solver was the small density gradients. Was the calculation of separated flows improved with the pressure based coupled solver, or is it inherent in all coupled solvers?

Thanks, Jason

Re: Fluent 6.3 first run
 

I tried pressure based coupled solver (CFX) for seperated flows and I must say I am not happy. (CFX users might be happy with it though).

Re: Fluent 6.3 first run
 

Thanks for the input! Jason

Re: Fluent 6.3 first run
 

I have a feeling that anysys might abandon CFX (or it might be lost in oblivian), the reason for thinking so is. We have seen pressure based coupled solver in Fluent. Than CFX has transition models for turbulence. Fluent has introduced transition model in 6.3 as beta function. So slowly we are seeing shifting of features from CFX. In the end ANSYS might not have any reason to develop CFX any further if Fluent can do the job. Good thing now is Fluent provides a lot of choices in terms of solvers.