• 한국산학기술학회논문지
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• 제10권10호
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• pp.2602-2608
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• 2009

비순정품 머플러는 경험에 의존하여 개발하는 경우가 다수이며, 국내에서는 그 해석과 평가가 미흡한 실정이다. 기존 비순정품 머플러는 지나치게 높은 압력강하량으로 인하여 엔진의 순조로운 작동을 저해하였다. 본 연구에서는 1500cc 가솔린 엔진의 비순정품 머플러의 압력강하량 저감을 위하여 각종 해석과 실험을 수행하였다. 다양한 모델을 실험한 결과, 동등한 흡음효과를 가지면서 기존의 비순정품 머플러 대비 우수한 압력강하량과 진동 특성을 가지는 머플러를 개발하였다. 개발된 머플러는 압력펄스에 기인하여 진동을 발생시키는 폐쇄된 공간을 배제하고 입구파이프를 이분화하는 구조를 가지고 있다.

• 한국산학기술학회논문지
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• 제10권10호
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• pp.2557-2564
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• 2009

본 연구는 70톤 급 초대형 중장비에 사용되는 머플러를 실험과 경험 법칙을 통하여 개발하였다. 머플러 내부의 파티션 플레이트, 천공관 그리고 파이프 구조를 변경하며 투과손실 성능을 비교하고, 실험 결과를 통하여 머플러의 성능에 영향을 미치는 내부 음향 요소의 최적 조합과 배치를 결정하였다.

• 한국자동차공학회논문집
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• 제17권4호
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• pp.24-31
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• 2009

This paper has been focused on the development of integrated automotive muffler system to meet getting more stringent sound quality target. Typically, muffler system consists of resonator and main muffler. The many varieties in exhaust pipe routing and the flexibility in muffler design make it possible to design an exhaust system to deliver tailpipe sound for specific sound quality requirement. In recent, it is strongly recommended that the function of resonator be merged into that of main muffler due to severe space limitation of underbody. The main objective of the paper is to study the effects of various geometrical parameters on the muffler performance. This work has succeeded in eliminating resonator without loss of muffler performance. This work has also investigated the effect of diameter of hole, geometries of pipes and location of muffler on the sound quality.

• 한국소음진동공학회논문집
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• 제25권2호
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• pp.83-89
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• 2015

The transmission loss(TL) has been widely used as the acoustic performance index of industrial mufflers. Industrial mufflers usually consist of several partitions with perforated plate. In this study, firstly, the computational model for a typical industrial muffler was performed and validated by comparing with the experimental results. Secondly, the effects of the porosity of the perforated plates on the acoustical TL were investigated and the database of the tendencies were set up. Finally, on the basis of these tendencies, the modified muffler with better TL than conventional one could be suggested.

• 대한기계학회논문집A
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• 제22권2호
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• pp.251-257
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• 1998

Active mufflers have been mainly applied in the large industrial engine due to considerable expense for implementation, but a necessity of development has been increased by the tightened regulation of exhaust noise and the request of high power. In this study, the active muffler prototype for installing in an automobile is designed and constructed. The active muffler is designed so that the primary noise and the control sound are propagated as a plane wave in the outlet. Therefore, the error microphone could be placed outside the high temperature centers of the tail pipe, and the noise radiating to the outside could be reduced in the whole areas around the outlet. For evaluating the control performance of the prototype, the control experiments of band-pass filtered random signal and the modulation of sinusoidal signal which are generated from the primary noise speaker as practical exhaust sound level are implemented. And to investigate the radiation pattern from the outlet of tail pipe and the noise reduction level of points placed adjacent to the outlet, the sound level of adjacent points of thirty is measured.

• 한국소음진동공학회논문집
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• 제15권9호
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• pp.1060-1069
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• 2005

Silencers are engineering devices that are designed to attenuate sound waves propagating in a flowing medium. The muffler type silencer has a series of chambers in parallel or series utilizing the reflection and expansion characteristics of the expansion chambers, sidetubes, branch resonators, and tailpipes to attenuate the sound. To Improve the performance of industrial blower silencer of muffler type which is employed in petrochemical plant, this paper seeks its optimal arrangement of buffs by experimental method and suggests optimal arrangement of buffs. Experimental results show that the optimal one suggested can reduce the noise level as much as 14 dB (or 18 dB(A)) in the laboratory and as much as 4 dB(A) compared to that of the existing silencer on the ground.

• International Journal of Naval Architecture and Ocean Engineering
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• 제6권4호
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• pp.935-946
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• 2014

This paper investigates the noise transmission performance of industrial mufflers widely used in ships based on the CAE modeling and simulation. Since the industrial mufflers have very complicated internal structures, the conventional Transfer Matrix Method (TMM) is of limited use. The CAE modeling and simulation is therefore required to incorporate commercial softwares: CATIA for geometry modeling, MSC/PATRAN for FE meshing and LMS/SYSNOISE for analysis. Main sources of difficulties in this study are led by complicated arrangement of reactive elements, perforated walls and absorption materials. The reactive elements and absorbent materials are modeled by applying boundary conditions given by impedance. The perforated walls are modeled by applying the transfer impedance on the duplicated node mesh. The CAE approach presented in this paper is verified by comparing with the theoretical solution of a concentric-tube resonator and is applied for industrial mufflers.

• 한국산학기술학회논문지
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• 제20권3호
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• pp.570-575
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• 2019

능동 머플러는 자동차 머플러의 배기소음을 저감하기 위하여 능동 소음 제어 기법을 적용하여 구현된다. 기존의 보편적인 Filtered_x LMS 알고리즘은 음향 궤환이 존재할 경우 제어필터의 차수가 매우 커지고 수렴성이 악화되는 문제가 있다. 이를 보완할 수 있는 Recursive LMS 알고리즘은 적응필터의 적응과정에서 쉽게 발산할 수 있어 적용이 제한되어 왔다. 본 논문에서는 수렴 성능과 계산량 부담이 개선되도록 1차 경로와 2차 경로 전달함수의 구조를 IIR 필터로 설계하였으며 IIR 필터 구조의 단점인 안정성 확보를 위해 안정화 필터 알고리즘을 적용하였다. 안정화 필터 알고리즘은 적응과정 중에 음향 궤환에 해당하는 전달함수의 극점이 발산하는 것을 방지하기 위하여 극점을 단위원 내부로 끌어 당기는 역할을 수행한다. 이러한 방법으로 능동 머플러 시스템의 계산량 절감과 수렴성능을 향상시킬 수 있다. 제안한 시스템의 유용성을 보이기 위하여 가변 환경인 디젤 엔진의 배기음향을 대상으로 기존의 Filtered_x LMS 알고리즘과 제안한 시스템과의 성능을 비교하여 그 우수성을 보였으며, 계산량은 절반 이하, 수렴 특성은 4배 이상의 성능을 보였다.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2009년도 춘계학술발표논문집
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• pp.139-142
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• 2009

본 논문은 1500cc 가솔린 엔진의 aftermarket 머플러의 성능 향상에 관한 연구이다. Aftermarket 머플러의 압력강하량과 소음레벨을 유동해석과 소음해석을 분석하여 제안모델들을 선정하였다. 제안모델들은 해석과 실험을 통하여 aftermarket 머플러 대비 우수한 아이들 소음특성과 압력강하량 저감효과를 확인하였다. 이러한 압력강하량의 감소는 엔진의 최대출력을 증대하는데 유리하게 작용한다. 결론적으로, 머플러의 각종 설계인자 분석 및 실험을 통하여 aftermarket 머플러의 신규 개선 사양을 제안하였다.

• Journal of Welding and Joining
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• 제30권6호
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• pp.15-20
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• 2012

Brazing technology has been widely used among bonding technologies because it enables to bond various metals, even ceramics, dissimilar metals, and give higher bonding strength, cost down, automation, etc. However, there are many parameters to achieve optimal brazing joint such as brazing alloys, brazing atmospheres, designs and brazing methods, etc. The brazing parameters affect seriously on the characteristic of final brazing products. Stainless steel is broadly used in high temperature applications, chemical industry, heat exchangers, muffler of vehicles, and so on. Accordingly, in this article, brazing alloys, forms of brazing alloys, brazing methods and atmospheres for stainless steel were described.