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http://dx.doi.org/10.5050/KSNVN.2002.12.5.355

Design Improvement via Structural Dynamics Modification - Application to Noise Reduction in Outdoor Unit of Air Conditioner  

Choi, Sang-Hyeon (한국과학기술원 기계공학과)
Park, Nam-Gyu (한국과학기술원 기계공학)
Park, Youn-Sik (한국과학기술원 기계공학과)
Publication Information
Transactions of the Korean Society for Noise and Vibration Engineering / v.12, no.5, 2002 , pp. 355-364 More about this Journal
Abstract
The goal of this research is to reduce noise level of an outdoor unit of air conditioner by changing its dynamic characteristics using SDM (structural dynamics modification) technique. At first, the emitting noise was measured and analyzed. The measurement records show the most critical frequency components which influences on the noise level. Then it was tried to move the natural frequencies outside the critical frequency region by SDM. Since it is very difficult to get a reliable FE model of air conditioner, experimentally measured frequency response functions were used to derive sensitivities that are very important to obtain design changes. The positions of modification and the thickness of modifying structures were determined to improve the dynamic characteristics of air conditioner. The recommended design guideline to move its natural frequencies outside the targeting frequency range was obtained. Then in order to prove its effectiveness, the changed design was experimentally tested and found that the SDM result is very effective to reduce not only its vibration but also its emitting noise.
Keywords
SBM(Structural Dynamics Modification); Structural Optimization; Sensitivity; FRF(Frequency Response Function); Air Conditioner;
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