Large Eddy Simulation of Cavitating Propeller Flows

Paper i proceeding, 2008

This paper deals with the simulation of cavitating flows based on Large Eddy Simulation techniques, combined with a volume of fluid implementation to capture the interface between liquid and vapor and a fairly simplistic and ad hoc model for the mass transfer between the phases. Two flows are considered: the first is over a three dimensional hydrofoil, and the second is a propeller operating in an artificially generated wake field. The cavitation over the hydrofoil displays a highly unsteady flow including important cavitation mechanisms due to side-entrant and re-entrant jet, shear layers and shed vorticity. Detailed experimental work is available, and partly revied in the paper, to validate the simulations. The propeller cavitation displays, apart from internal jets, also the upstream desinence as the blade exits the wake flow. In both cases the simulations give qualitatively very promising results, reproducing all the above mentioned mechanisms, although the cavity extent is slightly small. These results indicate that the techniques used in this work, may, in a near future, make it possible to gain in understanding of the processes of erosive cavitation and even constitute a predictive tool for cavitation nuisance.