Noise Improvement of Air Conditioning Accumulator Using Acoustic Metamaterials

There are many studies and researchers on MPPs and Meta Acoustic Materials, but there are many restrictions on the productivity and applicability that are actually applied to the product. For the product wise application, softness problems with MPPs and volumetric, three-dimensional, geometric problems with meta acoustic materials are some restrictions. To avoid this problem, a combination of two-dimensional steel plates and multiple small beams of grid shapes cantilever were produced. These corrections give good workability, productivity, spatial benefits, and pricing problems for the product. The sound absorption frequency characteristics were compared with the CAE analysis and test in the reverberation chamber with the reverse time to identify the characteristics of the steel plate unit. Although there were slight differences between analysis and test, the characteristic frequency domain showed excellent absorption versus other frequencies. It is actually applied to components used for air conditioning. Accumulator produces vibration and noise as pulsation of the pressure acts. In this reason, this sample was applied to the accumulator. First, we compared the characteristics of accumulator by air cycle alone, finally, in actual product conditions where refrigerant, temperature, pressure and flow rate exist within the cycle, sound pressure level and sound power was measured and compared. Some conditions gave good results and some conditions brought homework to be improved.