Topology optimization of a suction muffler in a fluid machine to maximize energy efficiency and minimize broadband noise
Nederland | Journal of Sound and Vibration
2015-05-14 | 바로가기
Cited by 5
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Journal of Sound and Vibration
Received 14 May 2015, Revised 7 September 2015, Accepted 21 October 2015, Available online 31 December 2015.
Seungjae Oha, Semyung Wanga, Sungman Chob
a School of Mechatronics, Gwangju Institute of Science and Technology (GIST)
b Home Appliance Laboratory, LG Electronics Inc.
A suction muffler used in a fluid machine has three functions: noise reduction; minimizing pressure drop and improving energy efficiency using acoustic effects. However, no method of suction muffler design considers all three of these functions concurrently. Therefore, in this study, we attempt to provide an integrated design method of a suction muffler in a fluid machine that considers all three functions. The topology optimization method for acoustic and fluid systems was applied to an integrated design. However, the interaction between fluid and acoustic was not considered. In addition, the acoustic input impedance of a suction muffler was used for a specific acoustical resonance frequency to improve the energy efficiency of a fluid machine. Finally, the sequential optimization method based on physical investigations was proposed to satisfy several design criteria. The proposed method was applied to the suction muffler in refrigerator׳s compressor.
A suction muffler is used to reduce the noise generated by a fluid machine and to minimize pressure drop. In addition, energy efficiency can be increased by the acoustic effect. However, until now, suction muffler design has focused on reducing noise and pressure drop induced by fluid flow. Considering the energy shortage in recent years, energy efficiency in fluid machines is particularly important. Therefore, we proposed an integrated design method for a suction muffler that considers three functions.
Designing for increased energy efficiency by utilizing acoustic pressure pulsation is related to a particular acoustical resonance frequency in the suction muffler. To match the target frequency, the magnitude of the real part of the input impedance was maximized. In terms of noise reduction, TL was maximized. In addition, to minimize the energy loss of the fluid flow, the power dissipation of the fluid flow was considered.
It was found to be difficult to determine the optimal design while satisfying all considerations. Therefore, in this study, a sequential optimization method was proposed based on physical insight. The idea of the sequential optimization method is to divide the design domain in the suction muffler depending on different considerations. Finally, the sequential design method proposed in this study was verified using various case studies. This method can be applied to other fluid machines as well. In this study, the average of transmission loss in low and high frequency bands of interest was maximized. However, if the extreme value of acoustic response within a frequency band is more important, the aggregated function approach  provides a more effective formulation of optimization model. In addition, normalized dimensionless objective functions may help to improve the convergence performance in a multi-criteria optimization problems.
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