Design optimization of inlet conduit in slanted axial-flow pump installation by orthogonal array experiment

Huang Jianyong;Zhang Feizhen;Zhang Hao;Yang Xiaoxia;Zhang Rui;Hangzhou Nanpai Engineering Construction Management Office;Shanghai Institute of Applied Mathematics and Mechanics,Shanghai University;

slanted axial-flow pump;;inlet conduit;;flow control;;hydraulic performance;;orthogonal design

In order to improve hydraulic performance of a slanted axial-flow pump installation at low flow rate conditions,a simple flow control method J-Groove was utilized to modify inlet conduit structure. J-Groove depth,length,number of grooves and groove stagger angle were selected to be design factors,and each factor has three levels,then nine design cases were determined by using orthogonal array experiment method. The unsteady Reynolds averaged Navier- Stokes equations based on the filter-based turbulence model were solved by using Ansys CFX to obtain the efficiency and head of each pump in those cases at low flow rates. Based on the range analysis method,the computed results were analyzed to get regularities that how the performance of the pump is affected by those factors. It was shown that the pump head is affected by the geometrical factors in the following order: groove depth,length,number of grooves and stagger angle,while the efficiency by the factors in the order: depth,number of grooves,stager angle and groove length. At last,an optimal design was established by using redesign analysis and compared with the original design. The results verified the function of the JGroove technique in suppressing unsteady flow in the impeller inlet and improving performance of a slanted axial-flow pump installation at low flow rate conditions.