Numerical analysis of cavitation about marine propellers using a compressible multiphase VOF fractional step method

In this study, the morphology of cavitation about two marine propellers (four bladed and two bladed) is investigated numerically. A compressible, multiphase Volume of Fluid method integrated with an advanced energy equation is employed to reveal the flow physics around the propeller. Low numerical dissipation is achieved with the use of a Kurganov-Tadmor central flux scheme and a compressible fraction step method for the pressure velocity coupling. The mass transfer source terms in the continuity, momentum and energy equations are modelled with the Schnerr and Sauer cavitation model which is modified to ensure the boundedness of volume fraction in each computational unit. Following this, a Ffowcs Williams and Hawkings formulation 1A model is utilised to approximate the acoustic pressure fluctuation caused by the formation and collapse of vortex cavity at the blade tip of the two bladed propeller. Qualitative comparison of the simulations and experimental visualisations demonstrates the good ability of the developed code to model propeller cavitation. Further investigations are needed to fully validate the acoustic model.