Good day Martin, I'm doing a research paper on an external gear pump and I'm applying the same models as for the lobe blower as it is essentially the same as an external gear pump but instead of air I just changed it to incompressible liquid (oil). I've spend quiet some time in the star ccm+ tutorial files trying to find out why we use the k-epsilon turbulent model and not the k-omega model, from what I can read I assume it is because the k-omega is sensitive to the value of omega in the free stream? But this issue was addressed by the SST K-omega model, so I'm a bit clueless on why we utilize the K-epsilon model then, any advice or pointers that would help me understand why we use that model would kindly be appreciated. kind regards Niel Joubert
The settings in tutorials are typically due to educational reasons or due to simplicity. Of course one can use these settings as a starting point, but for better results one has to adjust the cfd-model. For a gear pump I recommend the k-omega-SST turbulence model, which combines the advantages of the k-epsilon and the k-omega model.
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Good day Martin, I'm doing a research paper on an external gear pump and I'm applying the same models as for the lobe blower as it is essentially the same as an external gear pump but instead of air I just changed it to incompressible liquid (oil). I've spend quiet some time in the star ccm+ tutorial files trying to find out why we use the k-epsilon turbulent model and not the k-omega model, from what I can read I assume it is because the k-omega is sensitive to the value of omega in the free stream? But this issue was addressed by the SST K-omega model, so I'm a bit clueless on why we utilize the K-epsilon model then, any advice or pointers that would help me understand why we use that model would kindly be appreciated.
kind regards
Niel Joubert
The only other explaination is that K-Epsilon models offer a reasonable balance between accuracy, computational expense, and resilience
The settings in tutorials are typically due to educational reasons or due to simplicity. Of course one can use these settings as a starting point, but for better results one has to adjust the cfd-model. For a gear pump I recommend the k-omega-SST turbulence model, which combines the advantages of the k-epsilon and the k-omega model.
Thank you for your comment, I’ll compare the results to one another, maybe the difference is so small that one can use either models