Optimization design of the groove flow control technique to suppress flow instability in axial-flow pump

Abstract

Abstract As an effective fluid control technology, the groove flow control technique is used to improve axial-flow pump energy performance. Determining the values of groove parameters reasonably is essential to maximize the energy performance of axial-flow pumps. In order to solve the limitation of traditional groove design in groove flow control technology, this paper presents a multi-objective groove optimization method developed by integrating OD (orthogonal design), RSM (response surface methodology), and PSO (particle swarm optimization). A case study of an axial-flow pump is conducted. By using the OD method, the sample space has been designed. The performance prediction model of axial flow pump is established by RSM. In addition, the linear weighted method is employed to construct a comprehensive evaluation function as the fitness value of PSO. Finally, an optimal combination of the groove flow control technique parameters is determined using the PSO algorithm. The result shows that this method proposed in this paper is helpful for solving multi-objective optimization of the groove flow control technique and could effectively improve the hydraulic performance of the axial-flow pump under three typical stall conditions. The optimization effectively suppresses the formation of a saddle zone. In addition, the optimization increases the pump head by 0.30, 4.41 and 9.70 m under the critical stall condition, moderate stall condition and deep stall condition, respectively. Moreover, the optimization leads to better inflow conditions for the impeller and enhances its performance under the stall conditions. This study provides a basis for the early-stage design of the groove flow control technique for axial-flow pump and provides a valuable reference for the optimal design of groove for other fluid machineries.