[davood]

Dear friends

I have simulated savonius wind turbine in fluent but cp (power coefficient ) is more than 59%(multiple reference frame,unsteady,k-e standard model,...), it is 80%.whats wrong? what should i do to get a correct result?but i think i should set up sliding mesh model?!!what do you think?and i dont know how should i set up sliding mesh model, whats different among mrf and smm setting up?would you help me?


thanks with respectfully

[edoan]

does the compuational domain act in a way that "shrouds" the turbine? This could cause a higher cp

[davood]

I dont know what you mean?would clear it?

[edoan]

I just mean that 59 % limit exists because the air is expanding as it moves toward and through the turbine if you allow the air no room to expand and you are forcing it all through the turbine because the borders of your domain are too close to the edge of the turbine you may see a higher efficiency. Btw i think for VAWT the theoretical max efficiency should be even lower then 59 %

[davood]

thanks a lot dear

[davood]

I did that but results didnt change

[edoan]

According to fluent using MRF is "meaningful only for steady flow" perhaps this is something you should look closer into, Im sorry I cant give better advice.

[davood]

thanks dear

[davood]

hi dears
i have simulated savonius wind turbine but i dont know how should i calculate cp?cm which i have got ,are more than 1,is it possible(cm>1)?when i have defined pressure outlet boundary, should i set up reference pressure location?


thanks