Nai Xian Lu

LES of unsteady cavitation on the delft twisted foil

In this paper, the cavitating flow around the Delft twisted hydrofoil with unsteady inflow condition is numerically simulated using Large Eddy Simulation in combination with a volume of fluid implementation to capture the liquid-vapor interface and Kunz’s model for the mass transfer between the phases. Main cavitation mechanisms, including periodic shedding of main and secondary cavities, side- and re-entrant jets, as well as the cavity extent and the lock-in effect between the inflow variation and the cavity are compared with experimental observations.

Numerical Simulations of the Cavitating Flow on a Marine Propeller

This paper deals with numerical simulations of the cavitating flow around a marine propeller operating in open water but mounted on an inclined shaft. The investigation is mainly based on both Large Eddy simulation (LES) and Unsteady Reynolds-Averaged Navier-Stokes (URANS) in combination with a Volume-of-Fluid implementation to capture the liquid-vapour interface and a transport equation-based method for the mass transfer between the phases. Potential flow solver result will also be included to offer a complete picture of the general behaviour and capabilities of a range of computational methods with different levels of detail. Highspeed video recordings from experiments are available for detailed inspection.

Mesh Resolution Effects in Simulating Unsteady Sheet Cavitation

Abstract We present simulations of the cavitating flow on a NACA0015 hydrofoil in homogeneous and constant inflow. The simulations are performed using an incompressible implicit LES methodology with cavitation modelling based on a one-fluid mixture approach combined with a transport equation modelling including source terms for the mass transfer between the phases. We compare the flow development and spectral content of lift oscillations with experimental results from the literature. The study shows that a good qualitative as well as quantitative agreement is possible but requires a high mesh resolution, primarily in the wall normal direction, to avoid spurious cavitation dynamics in the simulated flow.