Unsteady Numerical Simulation of Cavitating Turbulent Flow Around a Highly Skewed Model Marine Propeller

Abstract

The cavitating flows around a highly skewed model marine propeller in both uniform flow and wake flow have been simulated by applying a mass transfer cavitation model based on Rayleigh–Plesset equation and k-ω shear stress transport (SST) turbulence model. From comparison of numerical results with the experiment, it is seen that the thrust and torque coefficients of the propeller are predicted satisfactory. It is also clarified from unsteady simulation of cavitating flow around the propeller in wake flow that the whole process of cavitating-flow evolution can be reasonably reproduced including sheet cavitation and tip vortex cavitation observed in the experiments. Furthermore, to study the effect of pressure fluctuation on the surrounding, pressure fluctuations induced by the cavitation as well as the propeller rotation are predicted at three reference positions above the propeller for comparison with the experimental data: The amplitudes of the dominant components corresponding to the first, second, and third blade passing frequencies were satisfactorily predicted. It is noted that the maximum difference of pressure fluctuation between the calculation and experiment reached 20%, which might be acceptable by usual engineering applications.

Probing Into the Effects of Cavitation on Hydrodynamic Characteristics of Surface Piercing Propellers Through Numerical Modeling of Oblique Water Entry of a Thin Wedge

“…Rb is the mean radius of the bubble and is assumed to be 1×10 -6 m, as proposed by Ji et al [34]. V  is the vapor fraction which is considered to be 5×10 -4 , as proposed by Mejri et al [35].…”

Hydroelastic analysis of surface piercing hydrofoil during initial water entry phase

“…is the mean radius of the bubble and is assumed to be 1 × 10 −6 m, as proposed by Ji [32]. is the vapor fraction which is considered to be 5 × 10 −4 , as proposed by Mejri [33].…”

A Multi-Objective Approach for Determining the Number of Blades on a Naca Marine Propeller

“…Therefore, the velocity vector is changed from the absolute form to the relative form according to r vv ωr , where r is the position vector relative to the origin and ω is the rotational velocity vector, and the governing equations are solved in the relative form. This approach is the simplest technique for modelling the problems with rotary boundary conditions, while the flow which is entering to the rotary part is uniform relative to the axis of rotation, in a steady state way and has been applied by many other researchers [4][5][6][7][8]. Hence, this technique is used in this research.…”

“…Therefore, the hydrodynamics researchers have been interested in simulating the flow around the propellers by means of RANS-based Computational Fluid Dynamics (CFD) methods for the last decade. Several research projects have been performed on marine propellers in open water or wake conditions using numerical methods [1][2][3][4][5][6][7][8]. For example, Ji et al (2011) [6] performed an unsteady numerical simulation of cavitating turbulent flow around a highly skewed marine propeller.…”