スプール弁内流れの可視化と三次元数値解析モデルの検討

抄録

This study describes a flow structure in the hydraulic spool valve in low pressure. The spool valve is made of acrylic resin with the spool diameter of 24 mm. Three slit widths of 0.8 mm, 1.2 mm and 1.6 mm are employed in the experiment. Flow pattern was visualized by laser sheet. A flow entered into a chamber of the valve was initially disturbed, and gradually regulated as two dimensional flow in annulus between two concentric cylinders (d=13 mm and D=24 mm). In this region, streamlines initially placed at middle of the annulus were sucked toward the spool surface. Some streamlines located near the wall of housing were suddenly bent upstream of a slit because of decreasing pressure. Downstream of the slit a jet was mixed with rotating flow at upper side, and on the other hand a vortex was generated at bottom side by a jet which collided a bottom wall of housing. Three dimensional numerical analysis was performed by a finite-element method for a downstream model and a full model under conditions of steady and turbulence. Results of numerical analysis in a full model agree with experimental ones.