Acoustic Radiation of a Cylindrical Bar and an Infinite Plate Excited by the Field of a Ship Propeller PDF Download

Author: Stavros Tsakonas
Publisher:
ISBN:
Category : Propellers
Languages : en
Pages : 230

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Book Description
In one instance, an infinitely long elastic beam with circular cross section and in another an in finite elastic plate are immersed in an acoustic fluid parallel to an operating marine propeller. The pressure field generated by the propeller and transmitted and radiated by cylindrical beam or plate is studied by means of Fourier transform techniques. Analytic expressions for the pres sure signals due to the scattering and radiating mechanisms are obtained at large distances from the disturbance and a study is made of their dependence on such important parameters as pro peller clearance, reduced frequencies, number of blades, propeller loading and geometry as well as the elastic properties of the boundary. Further more, closed form expressions of extreme sim plicity are developed for the propeller-induced vibratory force on the cylinder and on the plate. Numerical results are obtained on the assumption of constant loading for a 2- 3- and 4-bladed propeller at various distances and different pro peller clearances. The calculated sound pressures for realistic values of the parameters indicate that an appreciable sound level is obtained through the mechanism of the elastic boundary reaction to the propeller motion. (Author).