Correction to cavitation number reflecting the effect of air content in water

Abstract

The main parameter employed in descriptions of cavitating flows is cavitation number. This number should be calculated using the actual pressure within the cavity. However, the pressure in the cavity was not determined in many known experiments and the employed values of cavitation numbers were calculated using the vapor pressure instead of the actual cavity pressure there. This complicates interpretation of the experimental data and validation of computational tools. Meanwhile, as shown experimentally many decades ago, the pressure in cavities substantially depends on the inflow air content. A correction to the vapor cavitation number considering the impact of inflow air content and tuned to the experimental data from a single water tunnel is described in this article. This correction is validated with the various well-known experimental data. Such a correction makes it possible to revise the old experimental data and, as a result, to improve the agreement of the results of diverse computations with the corresponding measurements.