Throat cavitation number

Cavitation occurs when bubbles containing either vapor or gas are formed by reduction in the local pressure at constant temperature (Brennan, 1995 Knapp et al., 1979 Young, 1989) such as the rapid movement of the fluid past an impeller blade, through a pump, or in this case through a restriction (orifice) at near supersonic velocities. Quantifying the cavitation number is debatable, but it can be derived from the Bernoulli equation. Lush (Young, 1989) uses a throat cavitation number (aT) defined as... 

Experiments in the CaviMax to characterize the fluid flow varied the orifice size in the single-orifice processor from 1.75 to 6 mm (orifice removed). As mentioned before, the instrument operates at constant flow thus, the pressure of the measurement decreases as the applied orifice size increases. The flow measurements using this processor resulted in the ability to vary Reynolds numbers between 60,000 and up to 175,000, whereas the range of the available throat cavitation number was 0.85 to 1.7. 

Fig. 11. Three-dimensional surface plot showing the correlation of applied pressure, crystallographic strain, and Reynolds number-throat cavitation number for the synthesis of titania using the CaviMax processor.

CaviMax and CaviPro processors, 23-26 cavitational devices, 23-24 characterization of Reynolds and throat cavitation numbers, 25-27 classical approach, 18 copper-modified zinc oxide with crystallographic strain, 38-39 crystallographic strain by hydrodynamic cavitation, 34-39 engineered synthesis, 18-19 equipment for hydrodynamic cavitation, 21-22... 

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