A Calculation Method of Unsteady Propeller Cavitation using Quasi-Steady Calculation Results

Abstract

This paper deals with a calculation method to obtain the shape of unsteady cavity sectional geometry on a propeller blade operating in non-uniform wake field. The method make use of calculated cavity geometry by a quasi-steady calculation. This method is based on the consideration about a non-uniform flow field around a propeller blade section operating in non-uniform wake field. A calculation result based on present method show the suppression of cavity length and volume in cavity growing process, the phase delay of the maximum cavity volume and the acceleration of cavity collapse. This means that the hysterisys of the cavity length which was pointed out by Tulin could be expressed by present method. However, the decrease of the total cavity volume compared to the quasi-stady calculation result could not be clearly obtained. Moreover the detail geometry of cavity on the propeller blade does not coinside with the model scale expermantal results precisely. Further improvements are needed on these points.