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The flow characteristics and cavitation effects of water passing through small sharp-edged cylindrical orificesand valves of different shapes in water hydraulics are investigated. The test results using orifices with different aspect ratios and different diameters show that the flow coefficients in the case of non-cavitating flow are larger than that of flow inthe case of cavitation occurrence. The flow coefficients of flow with cavitation initially decrease as Reynolds number increases and ultimately tend to be of constant values close to contraction coefficient. Large aspect ratio has an effect ofsuppressing cavitation. The experimental results about disc valves illustrate that the valves with sharp edge at large opening are less affected by cavitation than that at small opening. Throttle with triangle notch has better anti-cavitation abilitythan that with square notch. The flowrate of the throttle with square notch is significantly affected by the flow direction orthe flow passage shape.
The flow characteristics and cavitation effects of water passing small small-edged cylindrical orificesand valves of different shapes in water hydraulics are investigated. The test results using orifices with different aspect ratios and different diameters show that the flow coefficients in the case of non-cavitating flow of of flow with cavitation initial decrease as Reynolds number increases and ultimately tend to be of constant values close to contraction coefficient. results about disc valves illustrate that the valves with sharp edge at large opening are less affected by cavitation than that at small opening. Throttle with triangle notch has better anti-cavitation abilitythan that with square notch. The flowrate of the throttle with square notch is significantly affected by the flow direction orthe flow passage s hape.