Impeller design and performance characteristics of a side channel pump

Abstract

Flow non-uniformity inherent at the impeller passages is realized to have pronounced effects in hydraulic pumps, which leads to severe operational challenges. Cutting the blade tip has emerged as a research hotspot, which is deemed to be a feasible and viable approach to mitigate flow-induced problems. Therefore, this paper reveals more insight into the inner flow phenomena in a side channel pump under different impeller geometry. First, five models of impeller blades are designed with different tip cutting angles ranging from 10° to 50°. Based on the experimental data and the reliable shear stress transport k-ω model, the turbulent flow nature of the pump was established by numerical simulations. The performance curves revealed that impeller model 2 attained the highest efficiency of 37.13% at the best efficiency point, although registering 26.9% and 32.9% at part-load and over-load conditions, respectively. At over-load conditions, the efficiency of model 2 improved by 3.46%, 3.13%, 2.21%, and 8.72% compared to models 1, 3, 4, and 5, respectively. The pressure distribution at the impeller passage was higher compared to the side channel of all the impeller models. Noticeably, each type of vortex structure occupies nearly all the impeller passages of the impeller models justifying the complicated flow in the side channel pump. Impeller models 1, 2, and 3 produced better flow exchanges with the higher mass flow in and out, hence stimulating improved energy conversion. The conclusion can provide a physical foundation for designers in selecting a reasonable tip angle for specific tasks from engineering perspectives.