[hadikhayyamian]

Hi All;

I am working on a dynamometer (you dont need to know what it is!!!), and for simplicity I changed its geometry as in Fig.1, as you can see water is inside a cylinder which contains a rotor spinnnig with angullar velocity of 5500 rpm. I set my Computational Domain like in Fig. 2. Note that there is no any inlet and outlet in this analysis to decrease computational difficulty.

Through my case setup in Fluent I did following:

1- Pressure Based- 2d Axisymmetric swirl (I dont know why I cant use just 2D Axisymmetric ??)- Absolute Velocity Formulation

3-Viscouse: I used Laminar, k-e and spalart-...

2- Material water; I assumed constant density

3- BC:

Fluid zone as single rotating frame (its rotation axis is x-axis as stated in Fluent Docs) , angular velocity of 5500 rpm

Rotor: rotating moving wall with relative velocity of zero (However I think I could set it as stationary wall as well. right????)

wall: rotating wall with absolute velocity of zero.

4- First Order Discritization Scheme for starting iteration and then shift 2 2nd order. For pressure I selected PRETSO! though.

5- operating pressure: about 3 bars, since I know from experiment its pressure is in that range.

6- initialization: just changed pressure from zero to 2 bar.

My results: Although solution converges, result is crazy. for example the inside pressure varies for -3 bar to 100 bar!

I also checked my Y+ value. it was alright.

I would appreciate if you reply anything you may think useful regarding my problem!

Regards.