Experimental Investigation of the Acoustic Source Location in an Inline Tube Bundle Subject to Cross Flow

Abstract

The flow induced acoustics in an inline tube bank (P/d=3) subject to cross flow, indicative of a generic heat exchanger geometry, are examined over a range of flow velocities using Particle Image Velocimetry (PIV) coupled with acoustic analysis. In this way, the spatial and temporal aeroacoustic source distribution has been determined experimentally. It is found that the acoustic sources are most intense behind the first row due to the compactness of the vortices. However, a strong negative source (i.e. a sink) is also present in this location, so that the effect of the first row wake is actually to suppress the acoustic resonance. In subsequent rows, the sources are weaker and more dispersed, but the sink is reduced dramatically. The result is that after the first row the entire array contributes energy to the acoustic field.