为研究粗糙度对离心泵进口回流非定常特性的影响，采用ANSYS CFX软件，基于RNG k-ε湍流模型和Rayleigh-Plesset方程的均相流空化模型，对某离心泵在5种不同的表面粗糙度(0、6.30、12.50、27.22和36.27 μm)下进行非定常计算，并分析小流量工况0.4Qd下回流旋涡的发展和不同断面压力脉动、进口和叶轮所受径向力。结果表明：随着流量的降低，效率受粗糙度影响越复杂；在Ra=6.30 μm时，各监测点的压力脉动幅值有一定的提高，在其他4个粗糙度下均有降低，且Ra=27.22 μm时，各监测点的压力脉动幅值降低程度最大；随着粗糙度的增大，进水管所受径向力先增大后缓慢增加，且受力中心偏心分布；叶轮受到的径向力与进水管壁面粗糙度有一定关联并分布复杂，在Ra=6.30 μm时，叶轮径向力趋于均匀分布。

To study the influence of roughness on unsteady characteristics of centrifugal pump inlet reflux,with ANSYS CFX software and based on RNG k-ε turbulence model and the homogeneous flow cavitation model of RayleighPlesset equation,the unsteady calculation of a centrifugal pump at 5 different roughness(0、6.30、12.50、27.22、36.27 μm)was performed.The development of the reflux vortex and the pressure fluctuations of different sections under the condition of 0.4Qd and the radial force of the inlet and impeller were analyzed.The results showed that with the decrease of mass flow,the roughness effect on the efficiency is more complicated.With Ra=6.30 μm,the pressure fluctuations amplitude of each monitoring point is improved,and it is reduced under the other four roughness.With Ra=27.22 μm,the pressure pulsation amplitude of each monitoring point is decreased to the greatest extent.As the roughness increases,the radial force of the inlet pipe increases first and then slowly increases,and the force center is eccentrically distributed.The radial force of the impeller is related the roughness of the inlet and the distribution of it is complicated.With Ra=6.30 μm,the radial force of the impeller tends to be evenly distributed.

TH311

四川省科技厅项目（2016JY0187）；四川省教育厅重大培育项目 （14CZ0013）