Hello everyone, 

I have a recurrent problem when meshing with SnappyHexMesh: there are "holes" on some boundaries of my mesh (see picture). Do you know why this is happening? And what could I change to have a mesh that perfectly match with my geometry? I am working on a passage of a centrifugal compressor. 

Thank you in advance !

Alex 

Hi everyone,

It seems to me that the field bounding limits are only applied in stationary simulations, and not in transient simulations. Indeed, in one of my transient tests, many cells of my domain reach values (the velocity in my case) well above the max velocity indicated in SIMULATION/Controls.

Are you aware of this comportment ?

Thanks in advance !

Zacharie

Hello everyone,

I have some questions regarding case initialization:

1) In steady-state simulations, I assume that the conditions defined in the "Initial Conditions" section are only used to initialize the first point of each speedline, and that subsequent points are then initialized from the previously calculated point in the speedline. Is that correct?

2) In transient cas...

Hi everybody, 

I ran a steady state + transient CFD simulation on a centrifugal compressor (with a k-omega SST model) and when post-processing the results and comparing the stationary part to the unsteady part of the calculation I have significantly different results. Indeed, the unsteady part shows a higher mass flow rate. This seems to be due to a higher flow speed and a...

Hello everybody,

I have a few questions regarding TCAE transient simulations.

Hello everybody, 

I am setting my first CFD transient simulation on a centrifugal compressor and I would like to know if you have any recommendations on the values of parameters like CFL number or PIMPLE algorithm settings. I assume that the default value of CFL number is relatively large (=20 hence >>1) because the PIMPLE algorithm is flexible and that's common to u...

Hi everyone,

I have a question concerning the mixing plane interface method : it seems to me that the method can generate numerical errors when reverse flow occurs on the interface.

To be more specific, I have a radial interface between the outlet of a centrifugal impeller and the inlet of its diffuser. On a specific zone of the interface, reverse flow occurs w...