Study On The Application Of Aeolian Tones Radiated From Jet Flow Past Tubes In Boiler Tube Leak Detection

The radiation characteristics of Aeolian tones from multi-tube situated in high-speed fluid cross-flow and its near-field flow are investigated. Use the 2-D Large Eddy Simulation in FLUENT to analysis unsteady turbulent flow field(Re>10000)around tubes and establish the numerical aerodynamic noise analysis model upon the theory of Lighthill acoustic analogy. According to vortex-sound theory, the noise generation mechanism and spectral characteristics are then analysed after the integral extrapolation method of FW-H(Ffowcs Williams / Hawkings) equations was utilized to solve sound field. The emphasis here is to research the influence on flow and sound field through changing the compressible fluid(0.3 <Ma <1) velocity、tubes spacing and arrangement, and then the acoustic radiation characteristics of the fluid impacting tube array is studied. The data analysis shows that tubes have the aerodynamic noise of broadband and a sound radiation characteristics of dipole coupling with quadrupole;acoustic radiation intensity can be increased caused by the flow rate increase, which is also related to the relationships between acoustic wavelength and pipe diameter;Parallel twin tubes have a critical spacing in frequency domain 0-3000 Hz, in which noise radiation intensity reaches the maximum; in three tubes cases, various arrangements will affect the sound radiation; The far-field acoustic radiation intensity is enhanced by increasing the number of tube rows. The study on the flow field and acoustic radiation characteristics of multi-tubes according to fluid dynamics simulation is feasible, it provides a reference for further researching the sound radiation mechanism and characteristics of tube array.