Numerical simulation and experimental research on the characteristic of pneumatic pressure measurement of spool valve orifice

The aim of this paper is to investigate the fluid dynamic behavior of a pneumatic pressure measurement method for the machining quality of servo-valve spool valves. By adopting a CFD technique, the numerical simulations of an ideal metering edge and a metering edge with round corner (fillet) of spool valve orifices are carried out respectively. Valve spool fillet is one of the major influencing factors for metering edge's pressure characteristic and nonlinearity of linearized characteristic curve Y−xv. The nozzle-flapper mechanism and the corresponding fixture are developed to replace ideal valve spool and sleeve. Finally, a pneumatic measuring experiment is performed to confirm and explain the simulation results.