[Nicholas Reza]

Hello,

I am modelling a fairly simple problem with a propeller, using sliding reference frame method. The physical testing boundaries are within a cavitation tunnel. I have completed the open water tests with good results. I am now attempting to partially block the flow (solid object covering part of the inlet- in an attempt to see the performance differences).

I was able to model cavitation in the open water tests, however the divergence was almost immediate and getting floating point errors with the blocked flow. I have removed multiphase and VOF and I am now attempting to solve the problem without the cavitation. I am still getting floating point error before 10 iterations.

Cell count ~2.1M
time step is for 1 degree of rotation and max time is set to allow 3 rotations.

models selected are: constant density, gradients, segregated flow, liquid, all y+, SST (menter), K-omega turbulence, RANS, exact wall distance, implicit unsteady, gravity, turbulent, 3D

I have interfaces on the required boundaries however, they are very close to the blockage. I am unsure if this will affect their abilities or not.

I hope I have provided enough information to provide an understanding of what I have and am trying to achieve.

Thanks,
Nick

[lcarasik]

Originally Posted by Nicholas Reza

Hello,

I am modelling a fairly simple problem with a propeller, using sliding reference frame method. The physical testing boundaries are within a cavitation tunnel. I have completed the open water tests with good results. I am now attempting to partially block the flow (solid object covering part of the inlet- in an attempt to see the performance differences).

I was able to model cavitation in the open water tests, however the divergence was almost immediate and getting floating point errors with the blocked flow. I have removed multiphase and VOF and I am now attempting to solve the problem without the cavitation. I am still getting floating point error before 10 iterations.

Cell count ~2.1M
time step is for 1 degree of rotation and max time is set to allow 3 rotations.

models selected are: constant density, gradients, segregated flow, liquid, all y+, SST (menter), K-omega turbulence, RANS, exact wall distance, implicit unsteady, gravity, turbulent, 3D

I have interfaces on the required boundaries however, they are very close to the blockage. I am unsure if this will affect their abilities or not.

I hope I have provided enough information to provide an understanding of what I have and am trying to achieve.

Thanks,
Nick

What are your boundary conditions?

[Nicholas Reza]

Hello Icarasik,

The boundary conditions are 'wall' for everything except the inlet (the large of two rectangles ahead of the propeller- flow is coming onto the propeller face), outlet at the opposite end and interfaces on all three surfaces of the rotating part.

Nick

[me3840]

Please post pictures of the mesh.

[Nicholas Reza]

Hello,

It's okay, I have worked my way through the problem and now have a perfectly running simulation.

Thanks to anyone who got back to me!


Nick

[cwl]

Thank you not - for not sharing the solution.
Others might come across with similar question.