Effects of blade angle on mixed-flow pump on internal vortex structure and impeller-guide vane adaptability
ZHAO Binjuan1, HAN Luyao1, LIU Yulu1, LIAO Wenyan1, FU Yanxia1,HUANG Zhongfu2
1. School of Energy and Power Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, China; 2. School of Material Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu 215600, China
Abstract：The blade placement angle of the rotary vane mixed-flow pump can be adjusted. When the working conditions change and the blade placement angle is adjusted, the adaptability of the impeller-guide vane will change accordingly, which will affect the hydraulic performance of the mixed-flow pump. A rotary vane mixed-flow pump with blade placement angles of -4°, 0° and 4° was taken as the research object. From the perspective of vortex structure, the influence of the change of blade placement angle on the adaptability of the impeller and the guide vane was explored. The results show that with the increase of the blade placement angle, the size of the internal vortex structure of the impeller gradually increases, and the diameter of the vortex band surrounding the rim gradually increases, while the number of vortices in the channel in the guide vane gradually decreases. The size and strength of the vortex structure on the cover wall behind the outer edge of the guide vane is gradually increasing; the stronger vortex of the mixed flow pump is mainly concentrated on the surface of the blade and the wall; by adjusting the blade placement angle, the rotary vane mixed-flow pump can maintain high-efficiency operation in different flow ranges, but as the blade placement angle increases, the efficiency of the rotary vane mixed-flow pump gradually decreases due to the gradual increase of the vortex structure. The number of channel vortices in the guide vane increases with the decrease of the blade placement angle, which leads to the reduction of the head of the rotary vane mixed-flow pump; the impeller-guide vane adaptability of the rotary vane mixed-flow pump changes after the blade placement angle is adjusted. When the placement angle is -4°, the match between the impeller and the guide vane is the best. The more deviated from -4°, the more vortex structures enter the guide vane from the impeller, and the worse the impeller-guide vane adaptability.
