AEOLIAN TONES RADIATED FROM LEAKAGE JET FLOW PAST HEAT EXCHANGER TUBES

In power plant boiler tube leakage monitoring, aerodynamic noise caused by leakage flow through the pipe array is one of the most important source. Theoretical research of aeoline tones around cylinder can effectively improve the accuracy of tube leakage detection technology. In this paper, it simulated flow around double tubes (in parallel and tandem arrangement) and three tubes with the methods of large eddy simulation (LES) and acoustic analogy based on FfowcsWilliams & Hawkings (FW-H) equation. The result shows that in the numerical simulation of double tubes, as the leak jet velocity increases, the far-field noise level increased gradually; the noise sound pressure has the maximum value when there is a critical spacing ratio L/D=3 in tandem twin tubes(L is the spacing between the centers of the two tubes and D is the tube diameter); for three tubes case, the SPL in the direction normal to the mean flow direction has symmetrical peaks about the horizontal axis, which are larger than the values in the flow direction. The simulation results can be the significant theoretical criterions for acoustic monitoring and diagnosis on boiler tube leak.