Cavitation in an Extremely Limited Flow Through Very Small Orifices

In order to clarify the role of cavitation nuclei upon inception, the behavior of inception was carefully investigated in an extremely limited water flow through very small orifices less than 1.0 mm in diameter under a prescribed nuclei condition. The following facts of technical interest were determined: a) The desinent cavitation number (σ_d) decreased rapidly and exponentially with the orifice diameter d, up to one hundredth in magnitude; and b) the cavitation appearance in such limited flows was quite different from that in fully turbulent flows through larger orifices.