A Study on Performance and Cavitation of Propellers for High Speed Crafts Including Effect of Boss

Abstract

SummaryIn the first report the authors discussed about the analysis in uniform flow.Using the same discrete model, the analysis for the present report was performed for the oblique case. In addition to the effect of boss, propeller slipstream asymmetry was also incorporated into the model. Experiments were performed by inclining the propeller shaft with respect to the flow direction in the cavitation tunnel.Predicted cavity extents had been found to agree relatively well with the observed ones when the predicted values were advanced by sixty degrees. In the calculation of pressure distribution on the blade, it had been found that there was a considerable drop in pressure at about 60% chord position of the blade near the boss and this position had been found to agree very well with the observed position of root cavitation erosion.