question about inflate layer in cfx mesh?
 

hi dear all
:confused:i have one geometry that following, i want inflate on wall , please advise me about Following questions:
1- my depth in inlet is 5m , height walls 8m, length geometry is 270m, i using element size 0.4 m, my question is :what inflation option do use? ( total thickness , first layer thickness,...) also number of layers is suitable and maximum thickness, first layer height?
unfortunately my Processor system is not very strong, So if yours possible
Please express your experience in this case.
thanks a lot

I do not have anyone to help me???

inflation is compulsory on all walls especially when using tet cells, although your geometry seems like it can be easily hex meshed. The choice of thickness is yours, depending on the physics of your flow, do you have any experimental data? Do you know what turbulence model you will be using? The inflation layer should be enough to capture the whole of the flow boundary layer. So, if you can approximate the boundary layer thickness just keep your inflation layer according to that. Add a few layer and generate results, then you can look at the boundary layer in the results if it is not good enough you can go back and add more inflation layer, reduce inflation thickness etc. Y+ values can be used which are available in the post processor to see if you inflation layer was good enough or not. For the first simulation you can also estimate the Y+ values based on you flow parameter and set the inflation layer accordingly.

dear hwet thanks for answer
:confused:i have experimental data, as i written in Previous Post,i used k-epsilon model, with consider depth of water d=5, whether i used first layer thickness or total thickness in inflate option??? Which is the most used?
thanks a lot