hello,am using the flow simulation to calculate the torque on a wind turbine
following this tutorial
i have noticed that he used internal study and set a computational domain
i have thought of using external study in same conditions,atmospheric pressure and air velocity,so i did 2 studies in external and internal
however i got completely different result,there is no significant deference in pressure or velocity before the turbine blades between the two cases
but the pressure and velocity is very different across it
pictures shows pressure cut plots of turbine cross section of the two cases,and theirs a big deference in pressure ,so the torques were very different
now why there is such a difference?and which one should i use?