Relating the Statistical Values of Turbulence to the Flow Induced Sound and resulting Mechanical Vibrations in Multi-channel systems

Our multi-channel system consists of two parallel pipes which are joined in to a single, larger pipe and transmits a high speed flow of Reynolds number ranging between 0.7 and 1.8 million. The turbulence, which is amplified by combining the two flows, results in large fluctuations in the fluid pressure. These pressure fluctuations lead to the production of sound, which excites the acoustic resonances of the system and in turn causes mechanical vibrations in the pipe. Using hybrid numerical simulation techniques, the investigations show that the sound pressure level and mechanical displacement magnitudes are interdependent on the Reynolds number of the flow and the frequency of the acoustic resonance. This behavior is linked to the turbulent energy spectrum at the location of the largest sound source for a certain Reynolds number. The frequency content of the turbulent energy is shown to determine the amplitude of the acoustic resonances excited in the system, and thus the mechanical vibration magnitudes in the pipe.