Delayed detached eddy simulation and vorticity analysis of cavitating flow around a marine propeller behind the hull

Abstract

Delayed detached eddy simulation (DDES) together with a homogeneous cavitation model is employed to investigate the cavitating flow around a marine propeller behind the hull. The cavitation influence on the simulation errors distribution and vortex dynamics is attached particular attention. The results indicate the predicted cavitation pattern and pressure fluctuation agree fairly well with the experimental results. Moreover, the three equations method is utilized to assess the simulation accuracy by calculating DDES errors. It is indicated that the propeller cavitation region exhibits large error values, especially for the re-entrant jet and tip vortex cavitation region. That demonstrates the occurrence of cavitation has a considerable impact on the errors distribution. In addition, the vorticity transport equation is applied to illustrate the cavitation-vortex interaction. From the results, the vortex stretching term is dominant among the terms, and the effect of the vortex dilation term is to transport vorticity from the sheet cavitation region to the tip vortex cavitation region. Finally, the hull wake influence on cavitation is also involved in the paper. It is noted that high wake region has a great contribution to the generation and development of cavitation.