湍流入流下泵喷推进器力谱特性研究

目的]旨在解决泵喷推进器在湍流入流作用下非定常力谱不明的问题.方法]通过湍流生成栅格和频谱合成法相结合的方法,产生具有时间脉动和空间相干结构的湍流,然后将此种方法与模拟相结合,获得泵喷推进器非定常力的宽带谱.结果]结果显示,所采用的计算方法能够获得泵喷推进器导管、定子和转子合理的非定常力宽带谱;泵喷推进器非定常力...

Study on force spectrum characteristics of a pump-jet under inflow turbulence

Objectives]This paper aims to clarify the characteristics of the unsteady force spectrum of a pump-jet operating under inflow turbulence.Methods]The turbulence grid and Fourier synthesis method are employed to produce inflow turbulence with spatial flow structure and temporal fluctuation,combined with large eddy simulation(LES)to obtain the broadband unsteady force spectrum of the pump-jet.Results]The results show that the proposed method can obtain the unsteady force broadband spectrum for the duct,stator and rotor.The unsteady force broadband spectrum of the pump-jet is composed of the’’humps’’around the blade passing frequency and its multiples,the characteristic line spectrum at the stator blade passing frequency and the shaft frequency of the adjacent stator multiples.As the number of blades increases,the’’humps’’become more obvious and the characteristic peaks change periodically and reach the minimum when the number of blades is equal to the number of rotors.Due to the use of the stator and duct,the amplitudes of the unsteady force broadband spectrum of the pump-jet are higher than those of the propeller,but the’’humps’’are not as obvious.Conclusions]The results of this paper can be helpful for clarifying the unsteady force characteristics of a pump-jet induced by inflow turbulence,and provide ideas for the vibration and noise reduction of pump-jets.