[Najmeh1981]

hello every one
According to the literature for horizontal axis flowmeters, I need to find the angular velocity corresponding to the geometry for each entrance flow rate and thus validate my solution. With mrf zone and a large
. .number of meshes, they have found the angular velocities corresponding to each mass flow rate with very good accuracy. By trial and error and using the line equation, they were able to find the angular velocity corresponding to zero torque. During the numerical solution, practically a small amount of torque remains on the impeller, and this moment is around -5 order or less . My favorite is its positive value.
In the Ansys tutorial, moving mesh is used to capture the effect of the stator on the flow path. Of course, if you solve with mrf first and then change to moving mesh, you will get the answer sooner.
I was able to improve the quality of the mesh and use the poly- hex mesh that I produced with Fluent Machining and Y+ less than two and a half, finally I was able to take the oscillation in the torque diagram on the impeller and finally reach a constant number, and then with the help of trial and error method, I will reach the angular velocity whose torque is approximately zero .I used mesh interface and mrf zone and k epsilon method and wall function for turbulence , and simple pressure method and the rest in the second order .
The graph of the residuals also looks good. The output flow rate is the same as the input flow rate with an accuracy of less than 0.3%.
I will send you a mass flow rate, for example.
(angular velocity of central impeller = 30.87 rad /s ( Experimental angular velocity

inlet velocity=0.5 m/s or 537 lit/ hour
The speed I get from numerical solution with Fluent is 21.5 rad/s, This is my problem, because this angular velocity is very less than experimental value.
I will be very happy to guide me
sincerely najmeh