fuad87
Subscriber

Hello Mr. Raef,


Let me explain in detail what I am trying to do. We have a cuvette of polystyrene (38x10x10 mm) partially filled with water upto 35 mm and rest of the space (3 mm) is filled with air. When we accelerate that cuvette (due to the nature of impact the acceleration profile is sinusoidal) we saw cavitation bubble formed. ( please check the published article to see the videos video). Now since the acceleration is sinusoidal in nature the pressure profile in cuvette is also sinusoidal hence when pressure drops below vapor pressure bubble starts to grow and then when pressure increases bubble starts to collapse. Now when I am turning off the mass transfer between the phases and check the pressure at the bottom of the cuvette I get very good sinusoidal pressure profile. Problem starts when I am turning on the mass transfer between the phases. As soon as pressure drops below vapor pressure I can see nice bubble formation but then the mixture pressure continue to decrease and goes to negative absolute pressure. So bubble never collapse rather elongate (stretched). Please see the detail of the problem.


detail of the domain


pressure profile at the right wall (bottom wall if tilted vertical)


bubble formation


bubble collapse


fluent simulation of absolute pressure at the right wall (bottom wall if tilted vertically)


fluent simulation of bubble grow


bubble stretching due to further pressure drop (negative abs pressure)


fluent simulation of static pressure (operating pressure 101325 pa) at the right wall (bottom wall if tilted vertically)