Does anybody know about any sucsess in modelling of cavitating flows using star-CD? I'd like to find references for the model description and results of calculations. Thank you.

Hi Bob!

STAR has 2 cavitation models: the barotropic one (based on a paper by Schmidt, 1999 [1]) and the bubble two-phase one (based on a paper by Kubota, 1992 [2]). The barotropic modle assumes a weak compressibility of both vapor and liquid for calculating the vaopr fraction. The bubble model uses the assumption of local equilibrium of a bubble cloud to set the vapor fraction. Practically, the barotropic model is best suited for internal or nozzle flows, whereas the bubble two-phase is found to give better results where bubble cavitation plays a major role, for instance for hydrofoils. Moreover, STAR has the capability to run the cavitation with a free-surface, i.e. you have a free-surface separating a light from an heavy fluid, and cavitation can additionnaly appear in the heavy fluid (see also the supplementary notes coming along STAR v3150A)

Cheers,

Frankie.

[1] Schmidt & al., Cavitation in Two-Dimensional Asymmetric Nozzles, SAE Technical Paper 1999-01-0518, 1999. [2] Kubota & al., A new modeling of cavitating flows: a numerical study of unsteady cavitation on a hydrofoil section, J. Fluid Mech., 240, 1992.

Hi

How do you say for sure that the Bubble model of cavitation is better suited for only external flows (flows of hydrofoils) and not well suited for internal nozzle flows?