A Systematical Study of the Influence of Blade Number on the Performance of a Side Channel Pump

Abstract

For side channel machines, distinction is made between side channel pumps and peripheral pumps. The blade number of side channel machines has a large influence on the performance of the pump. This is known from several experimental studies. For industrial side channel pumps, the blade number is between 20 and 26, whereas for industrial peripheral pumps, the blade number is much larger (between 36 and 90). In this paper, the influence of the blade number on the performance and the inner flow phenomena of different pumps will be investigated experimentally and numerically. The inner flow of the pump is examined in detail by computational fluid dynamics (CFD) simulations. Flow angles and velocities of the circulation flow between side channel and impeller are considered for different blade numbers. To explain the influences of the blade number, numerical results and theoretical formulas are combined. The experiments are carried out for two different modular side channel pump units, which differ in the side channel height h, the outer impeller diameter da, and the length of the blades l. So, the influence of the blade number can be studied in the context of other parameters like, for example, the relation between blade length and outer diameter of the pump. The obtained numerical results are compared with experimental data. Effects of the blade number on the performance curves of the pumps are shown by experimental and numerical results.