Transient analysis of the pre-whirl pump-jet propulsor with different blade numbers
Fuzheng Li, Qiaogao Huang, Guang Pan, Bilin Wu, Han Li
Abstract
In this work, the verified mesh is employed to study the effect of the stator number (Ns) and rotor number (Nr) on the pump-jet propulsor performance. Based on the RNG k–ϵ turbulence model, results show that the increase of Ns has an accelerating effect on flow velocity and improves the thrust and torque. The unsteady thrust characteristics are closely related to the combination of Ns and Nr. As Ns increase, the tip vortex intensity decreases and causes a reduction in pressure fluctuation on the rotor tip regime. While for the results of different Nr with constant area ratio, the steady performance almost unchanged. And the tip vortex moves upstream as Nr increases, this results in a stronger fluctuation on the rotor pressure side. Further study of cavitating flow indicates that the increase of Nr lead to an improve of the relative cavitation range, but the cavity volume decreases.