• 제목/요약/키워드: Silencer

검색결과 153건 처리시간 0.025초

500 Hz 이상 고주파수 영역에서 배기소음 저감을 위한 소음기 구조 (Silencer structure for exhaust noise attenuation performance in the high frequency range)

  • 김상암
    • 수산해양기술연구
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    • 제54권3호
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    • pp.255-261
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    • 2018
  • High power trends in the diesel engines due to engine downsizing do not provide noise attenuation that can be satisfied with the performance of the existing silencer on account of high frequency increases in the exhaust noise. This study improves the attenuation performance of the exhaust silencer of the diesel engine and suggests silencer structure that performs best attenuation performance, especially at the high frequency range in the exhaust noise. It proposes dual silencer structure with an average attenuation performance of 6.4 dB and a maximum of 10.7 dB in the high frequency range (over 500 Hz), and analyzes its characteristics compared with the existing silencer. The performance analysis is performed according to 'Measurements on silencers in situation-ISO 11820:1996 Acoustics' and describes the results of comparative analysis with the existing silencer.

흡음형과 공명형 덕트 소음기의 소음저감 성능에 관한 실험적 고찰 (An Experimental Investigation on Noise Reduction Performance of the Absorption and the Resonance Type Duct Silencers)

  • 이영섭;정광섭;이동훈
    • 설비공학논문집
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    • 제22권12호
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    • pp.897-901
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    • 2010
  • A silencer has been widely used for the purpose of suppressing the noises propagated from duct of air conditioning system. The absorption type silencer is usually applied to reduce the noise with high frequency bandwidth. On the order hand, the resonance type silencer is applied to reduce the noise with low-middle frequency bandwidth. The insertion loss of silencer is measured in the reverberation room. The cut-off frequency of reverberation room is 100 Hz. The insertion loss of absorption type silencer is more larger than that for resonance type silencer regardless of changing the flow velocity.

복합형 반사형 소음기의 음향학적 특성과 설계방법 (Design Methodology of Composite Reactive Silencer Based on Acoustic Analysis)

  • 김양한;최재웅;김영
    • 소음진동
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    • 제1권1호
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    • pp.29-38
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    • 1991
  • The performance of silencer system is controlled by the geometrical parameters such as the relative location of inlet and outlet ports, size of main chamber, and cross sectional geometry of inlet-outlet ports and main chamber of silencer. In addition to these parameters, the presence of mean flow and temperature gradient along the silencer also affects the acoustic characteristics of silencer system. Due to the complexity of silencer, it is not straight forward to design the appropriate silencer system. In this paper, a design methodology based on an oustic analysis of silencer system is proposed ; low frequency and high frequency tuning method.

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155mm 화포의 소음기 설계 및 시험평가에 관한 연구 (A Study on the Design and Testing of 155mm Howitzer Silencer)

  • 여철모;박성호;이해석;김영섭;정한식;정효민
    • 동력기계공학회지
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    • 제18권5호
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    • pp.144-149
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    • 2014
  • The silencer of 155mm caliber howitzer is developed to reduce its firing loud noise. This kind of research of a large gun was seldom because its big firing noise does not make significant effect even if to use silencer. Nowadays, military facilities became closely located civilian residential area. The noise would be regarded environmental pollution. So the noise reducing research becomes reconsidered. The previous silencer researches were only dealt with small guns as pistols and rifles moreover their theories was not properly analyzed for a large caliber silencer. The reason was previous researches of a large caliber silencer as 155mm howitzer were limited because their data based on simulation results without actual test by using computational fluid dynamics. In this study, the entire processes of silencer of 155mm caliber howitzer which were design, manufacturing, actual firing test, and analysis of its theories, were performed and showed. In particular, the actual noise of with silencer and without was measured and the results were compared to analyze the effect of silencer.

중구경 화포용 소음기 개발을 위한 실험적 연구 (An Experimental Study on the Development of Silencer for the Medium Caliber Gun)

  • 이해석;박성호
    • 한국군사과학기술학회지
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    • 제17권6호
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    • pp.725-732
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    • 2014
  • The silencer for the medium caliber gun was studied to reduce the propagation of gun-generated noise from the firing test range to the community. Three types of silencer were made to compare the reduction of sound pressure level and the effect of chamber volume and the exit angle to the reduction of sound pressure was considered. The structural analysis and measurement of pressure in the silencer showed that the structure is safe in terms of strength. The increase of recoil force to buffer must be considered in the development of silencer. The hypothesis test on the muzzle velocity for the existence of silencer showed that there are no difference at the significance level of 0.05.

대구경 화포의 소음기에 대한 수치해석 (NUMERICAL ANALYSIS FOR A SILENCER OF TANK GUN)

  • 고성호;이동수;우성대;강국정
    • 한국전산유체공학회지
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    • 제10권4호통권31호
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    • pp.59-65
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    • 2005
  • A numerical analysis was made to investigate the simple silencer for high pressure blast flow fields. Reynolds-Averaged Navier-Stokes equations were solved for an axisymmetric computational domain constructed by multi block grids. A blast flow field without the silencer was also calculated to validate the present numerical method. The effect of pressure diminution for the silencer was calculated by comparing with and without silencer at the atmosphere region. It was found that the tested silencer could achieve 89.4 percent pressure diminution.

공명기 배열을 이용한 중속 디젤엔진 배기 소음기의 저주파수 대역 성능 개선 연구 (A Study on the Performance Improvement of Medium Speed Diesel Engine Exhaust Silencer in the Low-frequency Range Using Array Resonators)

  • 김영현;주원호;배종국
    • 한국소음진동공학회논문집
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    • 제19권7호
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    • pp.693-698
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    • 2009
  • Various acoustic tests were carried out to investigate the acoustic performance of diesel engine exhaust silencers. In order to consider flow effects, the test facility was set up composed of fan, duct and silencer. Using the test facility, insertion loss tests were carried out to improve the acoustic performance in the low-frequency ranges. Through a series of tests, it was found out that the array resonators having multi-perforated holes inside the exhaust silencer, might be very effective in the low frequency range. Consequently, the hybrid-type silencer which is the combination of reflective silencer with array resonators and conventional absorptive silencer, was proposed and its high performance in the low-frequency range was also verified.

조합형 소음기를 이용한 박용 디젤 엔진 배기 소음 제어 (Exhaust Noise Control of Marine Diesel Engine Using Hybrid Silencer)

  • 이태경;주원호;배종국
    • 한국소음진동공학회논문집
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    • 제19권7호
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    • pp.679-684
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    • 2009
  • Low frequency exhaust noise of marine diesel engine is one of the most important noise sources in vessels. However, conventional absorptive silencers are ineffective to control exhaust noise because of low absorption in the low frequency range. In the paper, exhaust noise control of marine diesel engine was studied by using the hybrid silencer, which was composed of virtually divided array of concentric hole-cavity resonators and conventional absorptive silencer. A series of tests including field tests were performed to investigate the acoustic performance of the hybrid silencer. Consequently, its high performance of 5${\sim}$10 dB noise reduction in the low frequency range was confirmed and it is expected to be very helpful in reducing the exhaust noise of marine diesel engine.

건식진공펌프의 배기 소음 저감 (Exhaust Noise Reduction of Dry vacuum Pump)

  • 안영찬;이해진;이정윤;양정직;오재응
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2007년도 춘계학술대회논문집
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    • pp.349-354
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    • 2007
  • This paper considers acoustic analysis of silencer within a Dry vacuum pump. Main object is noise reduction of Dry Vacuum Pump using the silencer. First, we measured SPL and Intensity for noise source identification and then, designed for the silencer corresponding with noise character. 4-pole parameter are used for predicting transmission loss which is one of characteristics of silencer when we designed for silencer. Calculated Transmission Loss to change main effective factor and selected to optimal value using Design of Experiment. Finally, noise reduction is estimated to compare existing silencer with optimal silencer.

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배기 소음기내를 전파하는 비정상 충격파의 수치해석 (Study of the Weak Shock Wave Propagating through an Exhaust Pipe Silencer System)

  • 권용훈;김희동
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2001년도 추계학술대회논문집B
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    • pp.462-467
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    • 2001
  • The present study addresses a computational work of the weak shock wave propagatings inside a silencer system of automobile exhaust pipe. Four different types of the silencer systems and the initial shock wave Mach number $M_s$ of $1.01\sim1.30$ are applied to investigate their effects on the noise reduction and the flow field in a silencer system. The results obtained from the present computational work are compared with the experimental results. The second order total variation diminishing (TVD) scheme is employed to solve the two dimensional, compressible, unsteady, Euler equations. The present computational results predict the experimental results with a quite good accuracy. Of the four silencer systems applied, the most desirable silencer system to reduce the peak pressure at the exit of the exhaust pipe is discussed.

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