Prediction of propeller non-cavitation noise by superimposing shifted sound signal from an isolated blade

The time-cost of the propeller non-cavitation noise prediction can be greatly reduced by the isolated blade method,which is validated via hybrid URANS and acoustic analogy,followed by the acoustic characteristics of propeller in time domain are analyzed.Firstly,we predicted the sound of the E779 A propeller operating in uniform inflow and found a typical periodic characteristic of the sound pressure distribution on propeller blade as well as the sound signal of the receiver,and the result by the superimposing shifted sound signal from an isolated blade(isolated blade method) agreed well with the result by the integration on total blades,which validated the credibility of the isolated blade method in uniform inflow.Finally,we predicted the sound of a propeller running in the wake of submarine by the isolated blade method,and the result also agreed well with the result by the integration on total blades,which further indicated that the isolated blade method was also applicable for the non-cavitation noise prediction of the propeller running in non-uniform inflow.The noise prediction of the counter-rotating propeller,the pump-jet can also benefit from this method.