Experimental investigation on flow-induced noise of the underwater hydrofoil structure

A reverberation chamber method was proposed to measure the flow-induced noise of the underwater hydrofoil structure.A measurement system was established in the gravity water tunnel,the radiated sound power of the underwater hydrofoil model was measured using this method.It is investigated also that flow speed and structure parameter (thickness,rib and acoustic covering layer) have effect on the radiated sound power.The results show that the radiated sound power will increase with U_∞⁶.dependence(U_∞ is the flow speed) and show the dependence of radiated sound power on speed for dipole when U_∞ is less than 5 m/s;the radiated sound power will increase with U_∞^10±1 dependence and not indicate the dependence for dipole when U_∞ is more than 5 m/s;Flow-induced noise would be reduced by adding the model thickness,adding circum-ribs to it,or covering viscous-elastic material over it.The method is applicable for measuring the radiated sound power of complicated underwater structure and optimizing structural design.