Abstract:
The flow characteristics and cavitation effects of water passing
through small sharp-edged cylindrical orifices and 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 in the 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 of suppressing
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 ability than that
with square notch. The flowrate of the throttle with square
notch is significantly affected by the flow direction or the
flow passage shape.
Key words:
Cavitation Flow characteristics Small orifices Water
hydraulic valves
* This project is supported by National Natural Science Foundation of
China (No.59975031). Received June 14, 2001; received in revised form December 5, 2001; accepted April 1, 2002
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