1. State Key Laboratory of Mechanical System and Vibration, Shang Hai JiaoTong University, Shanghai, 200240)(2. 704 Research Institution, China Shipbuilding Industry Corporation, Shanghai, 200031
Abstract：Research on fluid exiting vibration of centrifugal pump volute is carried out. Firstly, based on the results of transient fluid flow by CFD simulation, three-direction orthogonal fluid exiting composite forces on volute are gained by integration the forces on interior fluid-solid surface of volute. Then compare among the three-direction composite forces both in whole transient simulation process and sole period is finished. As well as power spectrum analysis on these forces in the period that impeller rotates 360 degrees is done. At last, nine-order polynomial curve fitting, Fourier series and multi polynomial curve fitting are used to built mathematic model of three-direction single period fluid exiting forces respectively. The result shows that, the volute suffers three-direction periodical fluid forces whose frequency is the same as that of vanes in impeller passing volute tongue, and the direction of the first force which is perpendicular to the volute exit plane is opposite to the flowing direction and owns the biggest amplitude fluctuation in the three direction forces, while another direction of the second force which is perpendicular to the volute inlet plane is the same as that of the fluid flowing, the direction of the third force, whose amplitude fluctuation is the smallest, changes periodically. It also can be known that, peak of the second force and trough vale of the third force in single period both appear at the location that tip of vane passes the volute tough tangent line which crosses the center of impeller in the symmetry plane of volute, and the mathematic model by multi polynomial curve fitting has the smallest deviation from the original signal and less polynomial orders.
2012, Vol. 31 
