[HuseyinCan]

Hello guys i am trying to simulate a Savonius wind turbine with sliding mesh technique and k-epsilon realizable. Wind turbine placed at 0,0,0 where its shaft is on the y axis i am calculating it is torque as =torque_y()@blade (i have created named selection blade as wind tubine) then i am creating expression as torque with this function and get transient chart
1- With this values coming from chart should i take absolute value of them because many time torque values cross - part of graph.
2-Torque is always increasing with increasing TSR i mean theoratically at some point it should start to decrease i have tried different meshes but results is same what should i change ?

[HuseyinCan]

I have solved negative torque problem but still my torque value is too low torque coef. is around 0.085601721 and still have problem with 2 question torque always increasing with respect to TSR

[HuseyinCan]

I have added moment and residuals graphs i think they are ok but still i get really low torque values or i am mistaken my savonius wind turbine has H=0,2 m D=0,204m and inlet velocity is 10 m/s which makes possible torque around 0.254898‬ but i am getting my torque value is around 0.035 i really need help guys i am stuck at this point

[vinerm]

For a rotating system, you need to resolve the boundary layer, i.e., . And is preferable. Turbulence model will not make such a significant effect but wall treatment will. Furthermore, ensure that you have selected all the relevant walls responsible for generating torque.

[Aryo Yuwono Hasbi]

I get the same problem with Mr. Huseyin 2nd question. I've tried to use different model turbulence (i'm using SST on the first time, then changed it to k-w, standard k-epsilon, and RNG k-epsilon) but it keep makes the same pattern in TSR x Cp graph. The torque didn't reach the peak point and keep increased along with increase of TSR. I'm trying to simulating it in TSR 0,6-0,9. My Cp in TSR 0,8 is good (almost as same as experimental research with error 1,7%), but on the other TSR, it's not that good (the error is above 20%). Anyone can help us with this problem? (anyway, i'm using cfx)