Experimental Investigation of the Influence of different Leading Edge Modifications on the Sound Emission of Axial Fans downstream of a Heat Exchanger
* Presenting author
Axial fans have a major impact on the sound emission of technical systems. One of the common applications of low-pressure axial fans is their usage in air conditioning and cooling circuits. In most cases the fan operates downstream of a heat exchanger in this system. The suction side heat exchanger changes the upstream flow field of the fan and consequently the fan acoustic behavior compared to undisturbed inlet conditions. Investigations on sound emission of airfoils showed that leading-edge modifications like serrations or slits reduce the turbulence-airfoil interaction noise. In this study, the impact of three different leading-edge modifications (straight leading edge, sinusoidal serration and slits) on the sound emissions of a forward skewed low-pressure axial fan was examined. The inflow conditions varied between a free inflow and a disturbed inflow, generated by a heat exchanger located on the suction side of the axial fan. The results show that the modification of the leading edge has a positive influence on the sound radiation of the axial fan for both inlet conditions discussed above.