Limited Gradients for Viscous fluxes and Sources

andy

Dear all,

I've had good results with going from first to second order using linear reconstruction and then a limiter for scalar equations and the euler equations with step profile convection and shock tube simulations, respectively. This is on a cell-vertex based mesh using a Roe type scheme.

However, when I take a well converged first order solution, and then restart it with linear reconstruction with a limiter for a viscous flow, I get strange results. I am using the limited gradients for the viscous terms and the source terms for the turbulence model. I thought this would be correct and consistent, but when the simulation is run, the turbulence dies away.

When I change the source terms and the viscous fluxes to use the old unlimited grads, the solution appears to unaffected...at least as mentioned.

Is it correct to use the limited grads throughout, and should I expect to get a normal answer, hence I have a bug?? Or should I be using the limited grads just for the convective terms?

Does anybody have any experience with viscous flow behaving strangely when using limited grads?

Many thanks,

Andy