Prediction and parameter analysis of unsteady broadband thrust for pump jet

To predict the unsteady thrust of the interaction between pump jet rotor and turbulence, on the basis of the Sears function, and considering the influence of the turbulence, the prediction formula of propeller broadband unsteady excitation thrust was derived, which was verified by comparison with experimental values. Furthermore, considering the situation that the rotor of the pump-jet propeller works in the wake field of the leading vane, the turbulence wavenumber spectrum of the blade wake was established through the Gauss wake model, and the parameters of the blade wake field were calculated by empirical formulas. The prediction formula of the unsteady broadband force of the pump jet propeller rotor was derived. The broadband unsteady excitation thrust calculated by the formula was similar to the numerical calculation result. The influence of changes in flow field parameters on the prediction results of the propeller rotor broadband radiation noise was analyzed. Research shows that the turbulence intensity only affects the amplitude of the broadband unsteady excitation thrust prediction results, and the turbulence integral scale has a greater impact on the amplitude and spectrum shape.