Abstract: This study examines how to determine the main control sizes and their value ranges of the inflow and outflow passages of shaft tubular pump devices through statistical analysis of more than twenty typical large-scale pump sets of this type, aiming at developing a regularized design method. Using this new method, we design a large shaft tubular pump with an impeller diameter of 3200 mm for a practical project, and use numerical simulations of 3D turbulent flows to analyze hydraulic loss and flow behaviors including the velocity distribution and inflow angle of the shaft passage. Results reveal that the flows in the inlet and outlet passages are satisfactory with hydraulic losses of 0.065 m and 0.096 m respectively. And at the exit of inlet passage, velocity uniformity is 97.5% and flow angle is 87.7?. We conduct experimental tests on a 1:10.67-scale model, focusing on the measurement of energy characteristics. It shows that our shaft tubular pump set, based on the regularized design, achieves a high efficiency: 77.5% at an ultra-low lift of 1.08m, and 66% at the design point of Q = 25 m3/s and H = 0.62 m. These results would help optimize the hydraulic design of shaft tubular pumps.

Key words: pump set, shaft tubular conduit, regularized design, numerical simulation, scale model test