3.4. Performance of SP3 valve
Study of these results reveals that to equal the mass flow of the
standard valve the supply pressure can be reduced to approximately
100 kPa. At this pressure level maximum velocities
through the SP3 configuration are significantly lower, resulting
in minimum absolute pressures in the 70 kPa range. This a very
small pressure drop and it is not envisaged to have any adverse
effects on fluids passing through the valve. Conversely, the
user might opt to raise filling pressure to the point where
pressure drops inside the valve equal the previous model. If
the inlet pressure of the revised configuration is increased
until cavitation is incipient the model flows 8.07 kg/s. This is
the most efficient flow rate through the valve, as any furtherincrease in supply pressure results in flow separation at the
valve wall and the formation of a bubble, causing choking of
the flow. This point corresponds to a supply pressure of 250 kPa
on the revised configuration, and represents a 59% increase in
mass flow over the standard valve. Fig. 15 is a graphic illustration
of the flow performance of the SP3 valve.