• 제목/요약/키워드: Silencer Case

검색결과 7건 처리시간 0.016초

가상 트라이아웃을 이용한 소음기 케이스 성형에 관한 연구 (A Study on Forming of Silencer Case Using Virtual Tryout Method)

  • 고대림;이경식
    • 대한기계학회논문집A
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    • 제34권9호
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    • pp.1167-1173
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    • 2010
  • 본 논문에서는 가상 트라이아웃 방식을 이용하여 소음기 케이스의 성형에 관한 연구를 수행하였다. 먼저 사각 블랭크로부터 성형 중 변형이 일어나지 않는 부분을 코너컷하여 적정 블랭크를 설계하였고 파이프 삽입부와 어깨 반경부에 발생하는 주름을 방지하기 위해 적정 드로비드를 설계하였다. 마지막으로 파이프 삽입부 주위에 발생하는 주름과 파단을 방지하기 위해 형상비드를 설계하였다. 가상트라이 아웃방식으로 결정된 성형조건에 따라 소음기 케이스의 시제품을 제작하고 해석결과와 비교한 결과 시제품의 성형성, 두께 분포 등이 해석 결과와 잘 일치함을 알 수 있었다.

실사격에 의한 소음기 특성 평가 (An Evaluation of Silencer Characteristics by Live Firing Test)

  • 강국정;고성호;곽영균;이덕주;이인철
    • 한국군사과학기술학회지
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    • 제10권3호
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    • pp.217-224
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    • 2007
  • The present work addresses an experimental study on sound attenuation characteristics of silencer by live firing test. When a gun fires, there exists excessive noise which propagates as a form of blast wave. As muzzle energy of the weapon systems increases, the level of impulsive noise also increases. It is well known that the impulsive noise from a gun gives a serious damage to human bodies and structures. The adverse effects of impulsive sound also cause both social and military problems. So it is very important to study the characteristics of the impulsive sound attenuation. The live firing test is performed to evaluate the effect of four different silencers. The test result is compared with the case of bare muzzle which is not installed the silencer. The frequency characteristics are also analyzed to investigate the diminution of sound pressure level. The results of this study will be helpful to the designing silencer for large caliber weapon systems.

터보냉동기의 소음원 파악 및 저소음화에 대한 연구 (A Study on the Identification of Noise Source and the Noise Reduction Method of a Turbo Chiller)

  • 전완호
    • 한국유체기계학회 논문집
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    • 제7권3호
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    • pp.7-13
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    • 2004
  • In this paper, we identify the noise source and the path of a chiller. This chiller is newly developed for R-l34a refrigerant and 250 RT cooling capacity. The measured overall SPL of the developed turbo-chiller is about 100 dBA. Due to the high rotating speed of the centrifugal impeller, the nun noise source of the chiller is the blade passing frequency and its higher harmonics of the centrifugal impeller. This generated soundpropagates through the duct, and then transmits and radiates to the outer field. From the experiment, it is found that the high frequency noise is mostlytransmitted and radiated through the elbow duct, but the low frequency noise is transmitted and vadiated through the condenser wall. Therefore applying the absorbing material is an effective way of reducing the high and low frequency noise simultaneously. Measurement results show that the application of the sound absorbing material to the elbow duct reduced the overall sound pressure level by 4 dB compared to the 9 dBA reduction for the case of full enclosure. In order to control the generated noise, a dissipativetype silencer is also designed and tested. The silencer reduced the radiated noise about 7.5 dBA.

관내 유속을 고려한 상선의 배기관용 소음기의 성능실험연구 (An experimental study on the performance of silencers for exhaust merchant ships considering air flow velocity)

  • 엄재광;김사수
    • 대한조선학회논문집
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    • 제38권1호
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    • pp.108-115
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    • 2001
  • 선박의 주기관 및 발전기의 실린더내의 폭발소음은 배기관을 통하여 연돌 상부에서 전파되어 인접한 거주구 상층부 및 bridge wing 등의 소음을 증가시키는 주 요인이 되고 있다. 본 연구에서는 실제의 배기관인 400mm 및 600mm의 지름의 관에 대하여 0m/s 및 32m/s의 유속에 대하여 25dB 및 35dB silencer에 대하여 감음 성능을 실험하였다. 관내 유속은 축류 팬에 의하여 발생시켰고 실제 소음기(silencer)를 사용하여 감음 성능을 실측하였다.

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CFD를 이용한 선박 기관실 공기 공급용 팬 입구 형상에 따른 성능 비교 연구 (The Study of Performance Comparison on the Inlet Shapes of Fan for Engine Room of Ship Using CFD)

  • 권도훈;홍윤균;구성우;정은수
    • 대한조선학회 특별논문집
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    • 대한조선학회 2011년도 특별논문집
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    • pp.25-31
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    • 2011
  • The performance of fan for engine room of ship is absolutely important when it take into consideration work efficiency, work condition, and the performance of various equipments. Fan performance test should be carried out during sea trial to satisfy owner's requirement as above mentioned. We have considered various values to affect fan test result. In here, various values are to be silencer, fan inlet shape, and arrangement of fan room. In general, the shapes of fan inlet is overall circular type because of the shapes of axial fan. So, all vessels built at SHI have been applied fan inlet of circular type. And now, in order to reduce sound of noise from supply fan, big silencer often has been installed at high value vessels. In this case, the capacity of supplied air can be insufficient due to silencer which is an obstructer about air flow. In this paper, we have studied the performance of fan through comparison between a circular shape and a square shape of fan inlet. We also compare with CFD results and experimental results.

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다공형 배기 소음기의 성능에 관한 연구 (A study on the performance of the perforated tube exhaust muffler)

  • 권영필;이동훈;방정환
    • 오토저널
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    • 제14권6호
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    • pp.48-59
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    • 1992
  • This study is on the performance of the perforated tube muffler when it operates as an exhaust silencer with through-flow, steady or pulsating. Theoretical estimation of the insertion loss was made by means of transfer matrix and by using the impedance equation for the perforated tube obtained for the case of low-speed steady through-flow. Experiment was performed for the measurement of the insertion loss at two flow conditions. The one is a steady flow from the exhaust pipe of an idling diesel engine. The effect of the through-flow velocity and steadiness on the muffler performance was obtained. By comparing the theoretical prediction with the experimental result, the validity of the impedance equation in the theoretical model was discussed. It has been found that steadiness as well as magnitude of the through-flow has a significant effect on the performance of the perforated tube muffler. Especially, the self-noise due to the pulsating flow in the engine exhaust system must be taken into account for the prediction of the muffler performance.

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군(軍) 건설장비 소음의 전달 및 감쇠특성에 관한 연구 (A Study on the Propagation and Attenuation Properties of the Military Construction Equipments Noise)

  • 주덕훈;김재수
    • 한국소음진동공학회논문집
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    • 제20권9호
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    • pp.797-804
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    • 2010
  • In case of the construction equipment using by the military camp, such equipments are different from those equipments using at general construction site, of which muffler(silencer) is attached at the passenger seat side, since such equipments are obsoleted, it is great part that a considerably loud noises are continuously diffusing. When working, such noise can be influenced a lot of effects to those working soldiers nearby the equipment, and though it is really terrible loud noise as much as can arise a civil complaints by neighboring civilians, but because its specialty of the military, it is real state that there are many difficulties in establishing an effective soundproof countermeasure due to study shortage and lack of the relevant material regarding to military construction equipment. Accordingly, this study has ever grasped the characteristics of noise by its each frequencies and by distances about those 9 kinds of construction equipments using chiefly by the military camp. As the result, it was known that the military construction equipment is generating the loud noise which can influence bad effect to the workers, and such high sound pressure level of low frequency band can harm even to far distance.