... influential due to supra-regional laws.The primary structure-borne sound path is transmitted from the engine over the engine mounts into the ship's hull. This obvious path is currently already well attenuated and for the most part does not present noise vibration problems. Therefore, the secondary path from...

... Major sources of noise radiated by a ship to the oceans are briefly reviewed, focusing on the underwater noise radiated by the propeller caused by cavitating and non cavitating phenomena. Sheet cavitation and especially tip vortex cavitation are the most frequently first types of cavitation...

... Propeller cavitation, with all its noise, vibration, erosion, etc. is largely the consequence of blade lift fluctuations when operating in non-uniform inflow. It is easily shown, on the basis of simple low-aspect-ratio approximations, that forward-skew reduces the lift/incidence slope...

...-inception properties of the blade sections are determined and an empirical prediction of tip-vortex cavitation inception is included. Noise levels are estimated for operation with extensive cavitation on the blade. Several blade-pitch motions are evaluated and it is found that various forms of modified...

.... Propeller cavitation is an important cause of vibration and noise in the afterbody of present day ships. The highly skewed propeller investigated in the present day ships. The highly skewed propeller investigated in the present study was predicted to have better cavitation characteristics than...

... The recent concern for reducing ship noise has resulted in the necessity of treating propeller cavitation noise. In this paper a review of the work on tip vortex cavitation is used to begin a discussion of propeller hub and tip vortex cavitation noise. Model propeller noise measurements are used...

... The propeller noise induced in the accommodation spaces on as ship is a function of the acoustical source strength of the propeller ana of the response of the hull plates above the propeller. For a cavitating propeller the source strength is primarily determined by the volume variation...

... bronze, but not to propellers made of Mn bronze because of extremely high attenuation of sound waves. The report includes some detection examples of actual flaws showing fairly good agreement between actual size of flaw and that of detected results. diameter travel ni-al bronze noise probe...