Numerical Study On The Influence Of Inlet Guide Vane On The Internal Flow Characteristics Of Centrifugal Pump

The centrifugal pump is closely related to human life with the continuous and rapid growth of our society.The demand for centrifugal pumps with high reliability,stability,and efficiency is also increasing.Due to the requirements for changeable system equipment and working condition,a satisfying centrifugal pump needs to have the ability to operate under variable working conditions.In order to guarantee the efficiency and stability of centrifugal pump under different working conditions,guide vanes are selected to place at the inlet of the pump for adjustment of different working conditions.The CFD(Computational Fluid Dynamics)method is used to study the actual effect of the inlet guide vanes on the internal flow characteristics of the selected centrifugal pump at different flow rates.Besides,the influence of guide vanes with different positive offset angles at low flow rate point and the effect of 25°deflection angle on the internal pressure pulsation of pump has also been analyzed.Overall,the main work of this paper is as follows:1.Via the k-wSST model,the numerical simulation for the internal flow domain of the pump with and without the inlet guide vanes has been done.Based on the results,we compared the differences of the above four flow domains under different flow rates with and without the inlet guide vanes.The influence of the inlet guide vanes on the four flow domains under different flow rates has also been analyzed.The results show that the inlet vane has a better improvement effect on the internal flow of the centrifugal pump for the 0.4Q_d~0.8Q_d operating point.2.In order to study the effect of different positive offset angles for the internal flow domain of the pump,numerical simulation work has also been conducted for guide vanes with different positive offset angles.On the basis of the results,we compared and analyzed the distribution of velocity and pressure etc.in the internal flow domain of the pump with different pre-rotation guide vanes including zero pre-rotation angle.The results show that the best improvement of the flow field is obtained when the positive offset angle is 25°.3.The unsteady value simulation calculation was carried out at three small flow conditions for the centrifugal pump without inlet guide vane and the centrifugal pump with offset angle of 25°guide vane.Besides,the static pressure distribution of the volute and the pressure fluctuation of the tongue monitoring point and the pressure pulsation frequency domain of the volute section monitoring point and the tongue monitoring point is analyzed.The results show that the pressure pulsation amplitude of the 25°guide vane pump at each monitoring point is small,which is beneficial to improve the stability of the centrifugal pump operation.