Abstract: The unsteady forces generated when a pump-jet propulsor operates behind a submarine hull are a major excitation source for hull vibration and radiated noise. Accurate prediction of these forces is therefore central to the design of low-noise propulsors. This study presents a numerical framework that couples the prediction of tonal forces via unsteady Reynolds-averaged Navier-Stokes (URANS) equations with the estimation of broadband forces using large eddy simulation (LES). The framework is applied to a model-scale pump-jet installed behind the SUBOFF hull. Numerical simulations characterize the unsteady forces on the rotor and stator blades, yielding their respective tonal and broadband force spectra. The results indicate that the tonal force and moment fluctuations occur predominantly at the first and the second blade passing frequency (BPF), while the broadband force and moment spectra exhibit a distinct hump around the first BPF.

Key words: pump-jet propulsor, tonal force, broadband force, Reynolds-averaged Navier-Stokes (RANS), large eddy simulation (LES)

摘要： 泵喷推进器在艇后工作时产生的非定常力是潜艇振动与噪声的主要激励源之一,其精确预报是低噪声推进器设计的关键。该文针对自航状态下的泵喷推进器,分别采用非定常雷诺平均方法和大涡模拟方法,计算并预报其线谱力和宽带非定常力;对工作在SUBOFF艇后的泵喷推进器模型进行数值模拟,并分析了转子、定子的非定常力频谱特性。结果表明：线谱力(矩)主要出现在1倍和2倍叶频处,宽带力（矩）则在1倍叶频处存在驼峰。

关键词: 泵喷推进器, 线谱力, 宽带力, 雷诺平均, 大涡模拟