CAVITY RESONANCES IN A MULTI-COUPLED PIPE SYSTEM WITH EQUALLY SPACED CONNECTING HOLES

Abstract

Cavity resonances sometimes occur in pipe-like structures such as boiler exhaust ducts or heat exchangers. They are due to the self-sustaining oscillation mechanism. The noise is often eliminated by shifting the resonant frequencies away from the frequencies of the vortex generation. Thus the estimation of the resonant frequencies is of great importance in a practical sense. The calculation method of the resonant frequencies on the multi-coupled pipe system with equally spaced connecting holes was studied. It is found that the simultaneous equations derived by the acoustic modal analysis method can be divided into several independent groups due to the structural periodicity.