Enhanced Wall Treatment
 

Hello,

I'm having a problem when using a 2nd order scheme with enhanced wall treatment. The soultion deiverges until it crashes completely every time.

Has anyone experienced this before?

Any help is very much appreciated.

Thanks

Re: Enhanced Wall Treatment
 

Hi

What is the y+ for the first near-wall grid? Are you trying to model natual convection?

Re: Enhanced Wall Treatment
 

I'm unsure what the y+ value is but it looked reasonable.

Not natural convection but a gas turbine combustor model. I get this problem even when using only a turbulence model(no heat transfer). Every time I switch on enhanced wall treatment it diverges, with 2nd order sol.

Thanks

Re: Enhanced Wall Treatment
 

What turbulence model are you using?

What, precisely, is your typical yplus value? What is your mesh inflation factor near the wall?

Re: Enhanced Wall Treatment
 

Joe (and others),

I cant access my case file just now to get the y+ value but I'll get it asap.

I'm using the RSM because it is required for swirling flow. I need this more than enhanced wall treatment.

By inflation factor to you mean how much the density increases as I move away from the wall? The growth is 1.1 for 6 rows then it goes to a normal mesh.

When I put on enhanced wall treatment and only calculate the turbulence, the nturbulent viscosity is limited in cells but it eventually irons out and starts to converge. As soon as I solve all equations it crashes again. This has occured with various different grids for the same geometry.

As soon as I go into work I'll check the y+ value for 2nd order without EWT, but my laptop is currently in PC World being repaired.

Thanks very much

Phil