Aeroacoustic Simulation and Experimental Validation of Sound Emission of an Axial Fan Applied in a Heat Pump
* Presenting author
The reduction of noise emission of heat pumps is a major development target for the appliance manufacturer. An important source of sound is the fan. The fan is operating at disturbed inflow conditions due to installation in the appliance. Additionally small scale turbulence generated by the heat exchanger further increases fan noise emission. Noise emission may be reduced via improved installation or specific fan design. The aim of the project was to measure flow and turbulence characteristics inside the heat pump via constant temperature anemometry as well as noise emission. The acquired data set was then used for validation of CFD and CAA simulations. The effect of inflow turbulence was analyzed for configurations with and without heat exchanger. Hot wire measurements show increased average turbulence levels of 20 percent downstream the heat exchanger. In a second step URANS simulations were conducted for both configurations. The heat exchanger was modelled as porous medium. Turbulence properties could be matched with experiments with reasonable boundary conditions at the heat exchangers outlet.A LES-based CAA simulation of the heat pump was done for the configuration without heat exchanger. There is some deviation in flow rate but quite good prediction of sound power.