FLOW-INDUCED NOISE FROM SHORT ASPECT RATIO CYLINDERS INSIDE A RECTANGULAR DUCT

摘要

Flow-induced tonal noise and acoustic resonance problems are found in a variety of applications that range from nuclear power plant heat exchangers to automobile air conditioning evaporators. This tonal component of noise can be associated with the fluctuating forces produced in bluff bodies when subject to flow. Fluctuating forces can be represented as acoustic dipoles [Blake]. An acoustic model based on the inhomogeneous convected Helmholtz equation with a point dipole source term, volumetric damping and damping at the duct walls was used in conjunction with experimental measurements to study the acoustic field produced by short aspect ratio cylinders inside a rectangular duct with flow. The model was able to predict the acoustic field produced by the cylinders once an appropriate fluctuating lift coefficient was estimated and employed. Fluctuating lift coefficients found using the model and an optimization procedure were in reasonable agreement with results reported in the literature.