CFD Analysis of Steady State Flow Reaction Forces in a Rim Spool Valve
This thesis will consider the reaction (flow) force associated with a conventional spool land and one with a rim machined into it, and a modified form of the rimmed land referred to as a sharp edge tapered rim spool land. The rim and the sharp edge tapered rim were specially designed geometrical changes to the lands of the standard spool in order to reduce the large steady state flow forces (SSFF) inherent in the standard spool valve. In order to analyze the flow field inside the interior passages of the valve, three configurations of the spool were considered for orifice openings of 0.375, 0.5, 0.75 and 1.05 mm. Computational Fluid Dynamics (CFD) analysis was used to describe the fluid mechanics associated with the steady state flow forces as it provided a detailed structure of the flow through the valve, and to identify the flow mechanism whereby flow forces are reduced by the machining of a rim and tapered rim on the land of the spool. For all openings of the spool, the sharp tapered rim valve provides the largest reduction in SSFF. It was also observed that for all cases studied, the inflow SSFFs were smaller than for the outflow conditions.
The prediction of the steady state flow force on the rim spool was investigated in a flow divider valve configuration, and the results from the CFD analysis indicated a reduction by approximately 70%.
Advisor:Wu, Fang-Xiang; Schoenau, Greg J.; Evitts, Richard W.; Burton, Richard T.; Bergstrom, Donald J.; Bugg, James D.
School:University of Saskatchewan
School Location:Canada - Saskatchewan
Source Type:Master's Thesis
Keywords:flow reaction forces cfd measuring fluid jet angle in spool valve steady state rim
Date of Publication:02/20/2006