الفهرس | Only 14 pages are availabe for public view |
Abstract The object of the present thesis is an attempt towards a rational investigation of the noise problem viewed as a dynamic system. The model proposed in this study is a mono¬pole point source of noise moving with a constant speed either parallel or perpendicular to the ground (boundary surface) which is considered as a locally reacting surface of complex impedance. The characteristics of the sound field have been deter- mined in this model by reducing the wave equations of the to the one resulting from a stationary point moving system source but with a new boundary condition. Then, expressed the velocity potential function of the field has interms of powers of reciprocal of the distance from the image source.is The the sum of two components, namely, the direct wave from obtained results reveal that resultant sound field a moving in the free space and the reflected wave source which is a function of the direct wave, angle of incidence and retarded time. |