Investigation of Flow Structure Inside Spool Valve with Fem and Piv Methods

Abstract

AbstractIn this paper, the finite element method (FEM) and particle image velocimetry (PIV) techniques are utilized to obtained the flow field along the inlet passage, chamber, metering port, and outlet passage of a spool valve at several different geometrical dimensions. For numerical simulation, the stream function ψ and vorticity ω forms of continuity and Navier-Stokes equations are employed, and the finite element method is applied to discretize the equations. Self-developed simulation codes are executed to compute the values of the stream function and vorticity at each node in the flow domain. Then, according to the correlation between the stream function and velocity components, the velocity vectors of the entire field are calculated. For particle image velocimetry experiments, a pulse Nd: YAG laser is exploited to generate a laser beam. Convex and concave lenses are combined with each other to produce a 1.5–2 mm thickness laser sheet to illuminate the desired plane. Polystyrene spherical particles ...