FUNDAMENTAL CONSIDERATION ON NUMERICAL ANALYSIS OF UNSTEADY FLOW THROUGH SPOOL VALVE

摘要

The present paper deals with the numerical analysis on unsteady flow through a spool valve. Especially the effect of the spatial and temporal grid resolutions on the computational results is investigated. For the valve model of a simple geometry, unsteady flow was calculated for the step change of the supply pressure. Variations of the flow rate and the flow force were obtained for several values of the grid resolution and the time step. Comparison of the results revealed the complex convergence process of the relevant flow analysis. The transient response corresponding to the flow rate change does not much depend on spatial grid resolution and the time step. After the transition, the flow force is strongly affected by the time step, and its convergence with the grid refinement is rather slow, while the flow rate is not sensitive to the time step and converges with a relatively rough spatial grid resolution.