Influence of pump chamber structural parameters on axial forces and internal flow characteristics of mini centrifugal pumps

High-speed semi-open mini centrifugal pumps are widely used in aerospace fields because of their compact structure, stable performance, and self-cleaning ability. This study focuses on a high-speed semi-open mini centrifugal pump used in the temperature control circuits in satellites. Based on orthogonal experimental methodology, integrated with numerical simulations and performance tests, the influences of four different axial and radial dimensionless parameters for the rear pump chamber on the axial force and the unsteady flow characteristics are systematically investigated. The results show that the rear chamber cover force plays a dominant role in the direction and magnitude of the axial force. The dimensionless length ratio λ shows a monotonically increasing relationship with the total axial force. The increases in λ, ta, and ha are essentially the same, which is to raise the turbulence energy and pressure difference near the impeller outlet, thus to lead an increase in the total axial force. Moreover, reducing λ, ta, and ha can all reduce the total axial force, but adjusting λ is the most effective way to realize the object.