Study of leakage flow through a spool valve under blocked-actuator port condition-Simulation and experiment

The spool valve is the key component of hydraulic control system, and the performance of spool valve depends on its leakage behaviour. Again, the leakage flow of spool valve is highly susceptible to valve uncertain dimensions, radial clearance and overlap or underlap. In the present work, the relative performance of critically lapped, underlapped and overlapped valves has been demonstrated in terms of leakage flow rate and pressure sensitivity about the metered ports. An approach to explore uncertain dimensions of the valve has been developed using CFD as an investigating tool. The comparison of CFD prediction against experimental results has also been carried out. It is found that the CFD predictions are in excellent agreement with the experimental results.