Abstract:In order to study the influence of shaft on the hydraulic performance of low head tubular pump, CFD method was used to simulate thewhole pumping system including inlet and outlet water extension, inlet and outlet passage, impeller and guide vane. The influence of shaft length, shaft head profile and shaft tail profile on hydraulic loss of inlet passage, uniformity of axial velocity distribution at outlet section, weighted average angle of velocity at outlet section and energy characteristics of pumping system was analyzed. The results show that the hydraulic loss of the inlet passage and the weighted average velocity angle at the outlet section are affected by the shaft length, shaft head profile and shaft tail profile, but the uniformity of the axial velocity distribution at the outlet section of the inlet channel is almost not affected. Under the design flow rate condition, the hydraulic loss of the inlet passage with cone-shaped head and tail is 24% less than that of the inlet passage with arc-shaped head and tail. Therefore, the hydraulic performance of the inlet passage with cone-shaped head profile and tail profile is better, but when selecting the cone-shaped line, attention should be paid not to extend the tail length of the shaft. The results of numerical simulation were verified by model test. The two results are in good agreement, and the numerical simulation results are reliable.