[Battousai07]

Hello All,
I need to simulate the vapor formation inside of the piston as it moves and sucks fluid from a throttle. The problem is, the solved pressure and vapor fields are pretty random and unrealistic. Vapor is being formed at irrelevant locations. The simulation domain is shown at the attachments and here is a brief description.

-On the right hand side "Opening" with 3 Bara is defined. Only the liquid entrance is allowed. (Liquid Phase Fraction: 1, Vapor: 0
-Piston with green color moves towards to right hand side which causes the red region gets wider and sucks fluild from the throttle. (See attachments).
-System is initially filled with all liquid. Only vapor existence should be coming from the cavitation.
-Inıtial system pressure is uniform and 3 Bara

And here are the what have i tried and didn't worked so far.

-Simplified the model and created mesh with better quality (All hexa)
-Used adapted time step size with respect to "Co" and number of inner loop
-DoE for Cavitation parameters
-Repeated simulation with liquid and vapor couple that i know it solves perfectly for another case
- First order schemes to increase convergence. (Interesting thing is there were no convergence issues despite the inaccuracy it convergences perfectly.)
-Decrease the residual to eliminate random error as much as possible.

Those are the things that did not worked.
I need to calculate the vapor content and vacuum pressure inside of the piston. Thanks in advance for your helps.

[ghorrocks]

Can you post your output file, and an example image of what you are getting? You might also need to post an image showing what your boundary and mesh domains are if that is not obvious.