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-x_v. 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.