Ship noise is an important standard of the comfortability of the ship.The low and middle frequency noise in ship piping becomes the mainfactor of shipboard cabin noise while the noise caused by marine mainengines and propellers have been well controlled. Based oncomputational fluid dynamics (CFD) and Boundary Element Method(BEM), this paper analyzes the influence of inflow velocity, bendingangle, cross-sectional shape and cross-sectional dimensions, on thenoise of elbow pipes. The results show that the SPL frequencycharacteristics of elbow pipe outlet are similar at different inflowvelocities. The SPL peak frequencies of elbow pipe outlet are close atdifferent inflow velocities and the SPL of elbow pipe outlet increasesas inflow velocity increases. The noise level increases as the bendingangle increases, especially at low frequency. The noise level of circularsection pipe is lower than that of square section pipe. When thequantity of flow is a constant, the noise level decreases as crosssectionaldimensions increase. A damping material is attached to theelbow pipe for purpose of reducing the noise. The results indicate thatthe noise reduction effect of the damping material attached to elbowpipes is relatively effective.
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