Momentum source
 

Is there any way to give angular momentum source term in fluent? If not, how can one model rotation of mixer and the thrust produced by it?

momemtum source
 

Hi~
I met the same question with you and I created a cylinder zone as the mixer then added the momentum source term in this zone but I don't know how to calculate the value of the term. Do you know it?

Hi Lee,
Yes. The momentum source term (N/m3) can be calculated as the total thrust (N) produced by the mixer divided by the volume of cylindrical source (m3). However, I am sure if it is correct way to model mixer as mixer will also produce torque which we need to consider. I assumed only thrust to model our mixer as it is an axial mixer. Still I need feedback from other CFD experts on this forum to enlighten me more on this topic.

Manish

Hi there,



I've have experience with stirred tanks. From my experience, it depends on how complex you want your simulation to be. For 2D simulations, you could add fixed velocities that simulate the propeller via UDF. However, you need to get the velocities from experimental measurements. An example of this approach is tutorial 21 (using the Eulerian Multiphase Model for granular flow). However, you cannot get the thrust (I think this would be the torque) in 2D.



The other alternative is a 3D simulation of your propeller. In this case, you can set a MRF model (Steady state) or SM (transient state) and get the torque. Once again, it depends on what you problem description.