Multiobjective optimization of a tubular pump to improve the applicable operating head and hydraulic performance

Tubular pumps are widely used in irrigation and water conveyance projects. However, the operating head of most of these pumps is low, and only a few studies have focused on the design of an efficient tubular pump with a head more than 5 m, which is common in long-distance water supply projects. This work aims to improve the operating head and efficiency of tubular pumps while maintaining a low shaft power. The multi-objective orthogonal optimization method was used to determine the critical parameters of the tubular pump, i.e., blade number, airfoil, blade thickness and guide vane distance, and nine design schemes were selected. Next, by using computational fluid dynamics (CFD), a 3D model of the tubular pumps under different schemes was established, and the results were compared. Subsequently, the range method and weighted matrix method were utilized to find the optimized scheme. In addition, an experimental investigation was performed to verify the simulation and the performance of the designed tubular pump. The results indicated that the optimized scheme improved the operating head to 6.9 m with higher efficiency of 84.2% and a lower shaft power of 27.7 kW. The modeling results were in agreement with the experimental measurements, and the designed tubular pump had a wide range of high-efficiency zones