Investigation of Fluid Flow Through a Vane Pump Flow Control Valve

The recent development of a new vane-type pump for power steering applications involved paying special attention to the fluid flow dynamics within the pump casing, especially in the flow control or supercharge region, where excess pump fluid flow is diverted to the intake region. Durability testing of initial designs revealed the presence of cavitation damage to the pump casing in the supercharging region. Subsequent Computational Fluid Dynamics (CFD) analyses as well as experimental Flow Visualization studies aided in resolving the cavitation-damage problem.

The purpose of this paper is to describe the processes used in the CFD analyses and flow visualization studies. A two-dimensional (2D) convergence study was conducted to determine the CFD meshing requirements across the small orifice at the intersection of the flow-control valve and the supercharge port. An iterative procedure was employed to determine the operating position of the flow-control valve. The parallel flow-visualization studies were conducted with strobe-flash photography and videography through a window fabricated in the supercharge port. The window matched the port contours.

Modification of the flow-control valve face was shown by CFD and flow visualization to be one possible solution for the cavitation-damage problem seen in the pump casing. Comparative results are provided for review.