PRELIMINARY STUDIES OF THE SOUND GENERATED BY ORIFICES IN PIPELINES.
HYDRONAUTICS INC LAUREL MD
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The sound generated by orifices in pipelines was studied both analytically and experimentally. At low Mach numbers, the sound is generated by mass flow fluctuations caused by the periodic formation and shedding of vortices from the orifice edge. The sound produced has pure tones at a characteristic frequency and its lower and higher harmonics. At higher Mach numbers, the sound has a broad frequency base and is generated by the fluctuating force exerted by the orifice plate on the fluid. The study was extended to the noise generated by multiple orifices in the orifice plate. Experimental results are presented that verify the above analyses. Spectral density curves are given for the two types of sound generating mechanisms. Author