By means of the analysis of the internal flow within inlet passage of large pumping sta-tion, an analysis of 3-D direct boundary element for the flow has been presented on the potentialflow assumption, and a calculati...By means of the analysis of the internal flow within inlet passage of large pumping sta-tion, an analysis of 3-D direct boundary element for the flow has been presented on the potentialflow assumption, and a calculation and an experimental proof for the inlet passage of 30 angle-type axial pumping station have been made. Based on the analysis of the calculations and theexperiments, the calculation method is feasible and believable.展开更多
The flow patterns in the inlet and outlet conduits have a decisive effect on the safe, stable, and highly efficient operation of the pump in a large pumping station with low head. The numerical simulation of three-dim...The flow patterns in the inlet and outlet conduits have a decisive effect on the safe, stable, and highly efficient operation of the pump in a large pumping station with low head. The numerical simulation of three-dimensional （3D） turbulence flow in conduits is an important method to study the hydraulic performance and conduct an optimum hydraulic design for the conduits. With the analyses of the flow patterns in the inlet and outlet conduits, the boundary conditions of the numerical simulation for them can be determined. The main obtained conclusions are as follows： （i） Under normal operation conditions, there is essentially no pre-swirl flow at the impeller chamber inlet of an axial-flow pump system, based on which the boundary condition at the inlet conduit may be defined. （ii） The circulation at the guide vane outlet of an axial-flow pump system has a great effect on the hydraulic performance of the outlet conduit, and there is optimum circulation for the performance. Therefore, it is strongly suggested to design the guide vane according to the optimum circulation. （iii） The residual circulation at the guide vane outlet needs to be considered for the inlet boundary condition of the outlet conduit, and the value of the circulation may be measured in a specially designed test model.展开更多
Elbow-inlet passage is widely used in large drainage pumping stations.Flow uniformity at the exit section directly determines its hydraulic performance.Flow uniformity must be optimized to improve the operational effi...Elbow-inlet passage is widely used in large drainage pumping stations.Flow uniformity at the exit section directly determines its hydraulic performance.Flow uniformity must be optimized to improve the operational efficiency of the large axial-flow pumping station.Modeling and numerical simulation methods were used to investigate the elbow-inlet passage,and the accuracy of the calculation results was verified.The key geometric parameters affecting the uniformity of the flow were optimized by the orthogonal experiment design.The optimal schemes were obtained and compared with the original scheme.The results show that flow uniformity V u after optimization is 95.41%,which is increased by 1.04%.The pumping station efficiency is increased by 1.89%,thereby confirming the applicability and accuracy of the proposed scheme,especially for the optimization of flow uniformity of the exit section of the elbow-inlet passage.展开更多
A 2-D Lattice Boltzmann Method（LBM） coupled with a Sub-Grid Stress（SGS） model is proposed and validated by flows around a non-submerged spur dike in a channel.And then the LBM-SGS model is further applied to flows...A 2-D Lattice Boltzmann Method（LBM） coupled with a Sub-Grid Stress（SGS） model is proposed and validated by flows around a non-submerged spur dike in a channel.And then the LBM-SGS model is further applied to flows in a pumping-station forebay.Shallow water equations are numerically solved by the LBM and the turbulence can be taken into account and modeled efficiently by the Large Eddy Simulation（LES） model.The bounce-back scheme of the non-equilibrium part of the distribution function is used at the inlet boundary,the normal gradient of the distribution function is set as zero at the outlet boundary and the bounce-back scheme is applied to the solid wall to ensure non-slip boundary conditions.Firstly,the model successfully predicts the flow characteristics around a spur dike,such as circulating flow,velocity and water depth distributions.The results are verified by the experimental data and compared to the results obtained by conventional Smagoringsky Model（SM） of LES.Finally,the LBM-SGS model is used to further predict the flow characteristics in a forebay,such as secondary flow and water level.The comparisons show that the model scheme has the capacity to simulate complex flows in shallow water with reasonable accuracy and reliability.展开更多
文摘By means of the analysis of the internal flow within inlet passage of large pumping sta-tion, an analysis of 3-D direct boundary element for the flow has been presented on the potentialflow assumption, and a calculation and an experimental proof for the inlet passage of 30 angle-type axial pumping station have been made. Based on the analysis of the calculations and theexperiments, the calculation method is feasible and believable.
基金Project supported by the Natural Science Foundation of Jiangsu Higher Education Institutions ofChina(No.12KJD570001)
文摘The flow patterns in the inlet and outlet conduits have a decisive effect on the safe, stable, and highly efficient operation of the pump in a large pumping station with low head. The numerical simulation of three-dimensional （3D） turbulence flow in conduits is an important method to study the hydraulic performance and conduct an optimum hydraulic design for the conduits. With the analyses of the flow patterns in the inlet and outlet conduits, the boundary conditions of the numerical simulation for them can be determined. The main obtained conclusions are as follows： （i） Under normal operation conditions, there is essentially no pre-swirl flow at the impeller chamber inlet of an axial-flow pump system, based on which the boundary condition at the inlet conduit may be defined. （ii） The circulation at the guide vane outlet of an axial-flow pump system has a great effect on the hydraulic performance of the outlet conduit, and there is optimum circulation for the performance. Therefore, it is strongly suggested to design the guide vane according to the optimum circulation. （iii） The residual circulation at the guide vane outlet needs to be considered for the inlet boundary condition of the outlet conduit, and the value of the circulation may be measured in a specially designed test model.
基金Natural Science Foundation of China(51806053)Anhui Provincial Key Research and Development Program(1804a09020012,1804a09020007)
文摘Elbow-inlet passage is widely used in large drainage pumping stations.Flow uniformity at the exit section directly determines its hydraulic performance.Flow uniformity must be optimized to improve the operational efficiency of the large axial-flow pumping station.Modeling and numerical simulation methods were used to investigate the elbow-inlet passage,and the accuracy of the calculation results was verified.The key geometric parameters affecting the uniformity of the flow were optimized by the orthogonal experiment design.The optimal schemes were obtained and compared with the original scheme.The results show that flow uniformity V u after optimization is 95.41%,which is increased by 1.04%.The pumping station efficiency is increased by 1.89%,thereby confirming the applicability and accuracy of the proposed scheme,especially for the optimization of flow uniformity of the exit section of the elbow-inlet passage.
基金supported by the National Natural Science Foundation of China (Grant No. 50779069)the Beijing Natural Science Foundation (Grant No. 3083022)+3 种基金the Open Fund of Key Laboratory of Yellow River Sediment Research of the Ministry of Water Resources (Grant No. 200903)the National Science and Technology Supporting Programs in the 11th Five-Year Plan (Grant No. 2006BAB06B02)the Chinese Universities Scientific Fund (Grant Nos. 2009-1-90, 2009-2-12)the Program for Changjiang Scholars and Innovative Research Team in University (Grant No. PCSIRT0657)
文摘A 2-D Lattice Boltzmann Method（LBM） coupled with a Sub-Grid Stress（SGS） model is proposed and validated by flows around a non-submerged spur dike in a channel.And then the LBM-SGS model is further applied to flows in a pumping-station forebay.Shallow water equations are numerically solved by the LBM and the turbulence can be taken into account and modeled efficiently by the Large Eddy Simulation（LES） model.The bounce-back scheme of the non-equilibrium part of the distribution function is used at the inlet boundary,the normal gradient of the distribution function is set as zero at the outlet boundary and the bounce-back scheme is applied to the solid wall to ensure non-slip boundary conditions.Firstly,the model successfully predicts the flow characteristics around a spur dike,such as circulating flow,velocity and water depth distributions.The results are verified by the experimental data and compared to the results obtained by conventional Smagoringsky Model（SM） of LES.Finally,the LBM-SGS model is used to further predict the flow characteristics in a forebay,such as secondary flow and water level.The comparisons show that the model scheme has the capacity to simulate complex flows in shallow water with reasonable accuracy and reliability.
