Learning Forum

[Zexuan.Chen]

Hi I am doing a simulation on cavitation. If I have 3 phases in my model, phase 1 water, phase 2 water-vapor, phase 3 air, then in the Schneer-Sauer and Zwart-Gerber-BGelamri cavitation model, I can tell Fluent that the cavitation is from phase 1 (water) to phase 2 (water-vapor), but not from phase 1(water) to phase 3 (air), like the figure shown below.

However, in the Singhal cavitation model, for a 3 phases model, it seems I can not define the cavitation 'From Phase' and 'To Phase', like the figure shown below. The Singhal model always uses the first phase as liquid, and second phase as vapor. In this way, for a 3 phases model, could you please tell me in the Singhal cavitation model, if it is possible to define the cavitation is from phase 1 (water) to phase 2 (water-vapor), but not from phase 1(water) to phase 3 (air)?
Thank you.

[Karthik R]

Hello You can treat air and water vapor as two species of a mixture. To do this, you will need to enable the species transport model for this. Then, you will still have two phases - water and a mixture of air and water vapor. For mass transfer, you will need to select the "To Phase" as the water vapor species.
Karthik

[DrAmine]

Singhal model is quite old and is not recommended for usage.

[Zexuan.Chen]

Thank you for you reply, but Singhal model does not allow me to 'select to phase'. Unlike Zwart-Gerber-Belamri and Schnerr and Sauer models, I can not define the cavitation from 'water' to 'water vapor'. Like the picture shown in my question, there is no way to select 'to phase'.

[Zexuan.Chen]

Thank you for your reply. Could you please let me know which cavitation model suits ultrasonic cavitation? I read some papers, some of them using Singhal model. I used Singhal cavitation model and Zwart-Gerber-Belamri model for my simulation, but it seems they have different results.

[DrAmine]

For sure they will different results and the results will depend on the depth of the convergence. Zwart et al. or Schnerr et.al are fine. Same with Singhal but it based on an old implementation. Ultrasonic: are you moving something to initiate pressure waves / drop?

[Zexuan.Chen]

Thank you for your reply. Yes I am using dynamic mesh to move the boundary (frequency 120Khz), and the boundary is in the water. In this way, should I use Zwart or Scherr rather than Singhal? Also, should I set the water as 'compressible liquid' ?