• Title, Summary, Keyword: 소음예측프로그램

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A Study on Reduction Characteristics of Road Traffic Noise according to Arrangement Angle of Apartments (공동주택 배치각도별 도로교통소음 저감특성 연구)

  • Seo, Dong Ju;Kim, Nan Hee;Min, Kyoung Woo;Cho, Gwang Woon;Im, Kyeong Hun;Lee, Gi-Won;Jeong, Won Sam;Seo, Gwang Yeob;Jeong, Tae Ryang;Cho, Young Gwan
    • Journal of the Korean Society of Urban Environment
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    • v.17 no.4
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    • pp.339-349
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    • 2017
  • The purpose of this study is to analyze the characteristics of road traffic noise according to the arrangement angle and to provide basic data for the housing design by deriving the noise reduction prediction formula according to the building angle height. Noise measurement was carried out by selecting 18 measurement points for four buildings located at the same distance from the center line of adjacent roads for K apartment complex in Poonghyang-dong, Buk-gu, Gwangju city. As a result of the field test, it was analyzed that the buildings arranged at right angles to the road traffic noise source had a 2.2 dB (A) reduction effect compared to the buildings arranged in parallel, and the noise reduction effect tended to decrease as they went up from the low level to the high level. It can be confirmed that the reliability of the predictive program for deriving the noise reduction prediction formula according to the arrangement angle can be predicted within the mean error of 3.0 dB (A). As a result of simulating the arrangement angle of the building by 10 degrees from 0 to 90 degrees by using the noise prediction program, the reduction value ranged from 0.0 to 3.0 dB (A). The placement angle of the roadside building was 30 degrees and the height was 10 layers or more The noise reduction effect is more than 0.6 dB (A). The noise reduction value according to the arrangement angle was found to increase as the building height increased.

A Study on the Utilization of Computer Program for the Prediction of Rom Acoustics (실내음향 예측을 위한 컴퓨터 프로그램 이용에 관한 연구)

  • 김선우;최형욱;한명호
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.250-255
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    • 1997
  • The computer simulation and mock-up test are recently applied to the practical design for the room acoustics to predict and evaluate its characteristics. In this paper, the sound field properties predicted and evaluated by the computer simulation were compared to the measured data. Comparison and analysis between simulation data and measured data were performed for the Reverberation Time, Sound Pressure Level at the various measuring positions and frequencies and Definition, Early Decay Time, Speech Transmission Index.

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A Study on the Noise of Crusher for the Site-Recycling (현장파쇄시설의 소음에 관한 연구)

  • Lee, Jae-Sung;Kwon, Soon-Boum;Joo, See-Woong;Park, Seong-Yong;Bae, Kee-Sun;Jung, Jong-Suk
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • pp.392-395
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    • 2007
  • Recently, the construction wastes rapidly increase because of redevelopment, the development of new urbanization of large housing development, the expansion of social infrastructure. With increase of the construction noise caused by these developments, environmental conflicts and civil appeals increase. Moreover, the Government will reduce construction noise level to 65dB from 70dB in January 2009. Therefore, it will be expected to increase environmental conflicts and civil appels related to construction noise. To minimize environmental conflicts and civil appels, this study compared and analyzed measured noisy values of a crusher for the site-recycling to predicted value of simple noisy prediction program developed by "National Institute of Environmental Research". Based on the results, a crusher for the site-recycling can be arranged to minimize the noise.

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Noise Map Analysis for the Design of Noise Barrier at School Site (학교부지의 방음벽 설계를 위한 소음지도 해석)

  • Yun, Junho;Kim, Wonjin
    • Journal of Korean Society of Environmental Engineers
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    • v.34 no.4
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    • pp.232-238
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    • 2012
  • In this study, the noise mapping simulation is executed to design an effective barrier reducing noise levels of a school site. The geographical features of the ambient site and the school buildings are modelled in detail in order to consider sound propagation, deflection, and absorption phenomena etc. The main sound source, sound power level of expressway, is estimated on the basis of measured noise levels at several points of the site. The noise mapping simulation is performed by using ENPro, environmental noise prediction program based on ISO 9613 to analysis the effectiveness of noise barrier. Consequently, the noise barrier is designed to meet an environmental noise standard and satisfy low cost and safety conditions.

Noise Evaluation of Turbo Fan Aircraft(C525) in the Airfield (비행장에서의 터보 팬 항공기(C525) 소음 평가)

  • Kim, Woo-Jin;Ryu, Jong-Hyeon
    • Journal of the Korean Society of Mechanical Technology
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    • v.20 no.5
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    • pp.691-696
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    • 2018
  • Noise is unwanted sound and nerve jarring sound or mentally and physically harmful sound to the human body. In the 20th century, the aviation industry have been comprehensive industry of all areas and humanity have been globalized, the number of aircraft operated have been increased continuously. We confirmed that the actual measured noise data was consistent with the aircraft average noise data to calculate noise maps of INM version 7.0. and based on this, the actual flight scenarios and the noise map were created. For making the noise map, we assumed that the maximum number of flight is operated.

Development of Cabin Noise Prediction Program Induced by HVAC System (공조시스템 유기 격실 소음 예측 프로그램 개발)

  • Kim, Byung-Hee;Kwon, Jong-Hyun;Cho, Dae-Seung
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.554-558
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    • 2004
  • In this paper, we introduce noise prediction program of HVAC system to assist low-noisy design of ship's cabin. The developed program calculates sound power levels at HVAC components considering primary and secondary noise generated by fan and duct element, duct element noise attenuation, and duct break-in noise based on the authentic empirical method suggested by NEBB and acoustic power balancing method. Sound pressure level at cabin with or without ceiling system is evaluated by the diffuse-field theory considering diffuser and duct break-out sound powers. Moreover, the program provides intuitive pre- and post-processors using modem GUI functions to help efficient modeling and evaluation of cabin and HVAC component noise. To validate the accuracy and convenience of the program, noise prediction for a HVAC system is demonstrated.

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Three-dimensional analysis of the mufflers by BEM (경계요소법에 의한 소음기의 3차원 해석)

  • 윤제원;임정빈;권영필
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.19-24
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    • 1995
  • 단순한 형상의 소음기는 평면파이론에 의해 비교적 간단하게 음향성능을 해석적으로 구할 수 있다. 그러나 소음기의 형상이 복잡해지거나 해석하고자 하는 주파수의 범위가 평면파의 차단주파수 이상이 될 경우 소음기 내부의 음장이 평면파에서 벗어나게 되어 평면파 이론에 의한 해석은 실제와 상당한 오차가 발생하게 되므로 음장에 대한 3차원 해석이 필요하다. 이론적으로 3차원 문제를 해석할 수 있는 경우는 형상이 극히 단순한 경우에 국한되므로 유한요소법(FEM), 경계요소법(BEM)과 같은 수치해석적인 방법이 이용되고 있다. 경계요소법은 적분 커넬(kernel)의 특이성(singularity) 문제가 있지만 대상 영역의 경계면만을 이산화함으로써 모델링에 소요되는 시간과 노력을 절약할 수 있으므로 음향문제 해석에 있어서 효율적인 방법이라고 할 수 있다. 본 연구의 목적은 3차원 경계요소법 프로그램을 개발하고 평면파이론에 의한 해석이 어려운 여러가지 형태의 소음기에 대한 음향성능을 예측하고 실험으로 검증하는것이다. 특히, 단일영역으로 해석이 불가능한 다공형 소음기에 영역분할법을 적용하여 계산하고 결과를 검토하였다.

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Noise Analysis of Turbo Prop Aircraft(C90GT) (터보프롭 항공기(C90GT)의 소음 분석)

  • Ryu, Jong-Hyeon;Kim, Woo-Jin;Kim, Gyou-Beom
    • Journal of Convergence for Information Technology
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    • v.9 no.9
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    • pp.141-146
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    • 2019
  • The aircraft noise analysis area in this study is a training airfield where various kinds of aircraft are operated. It is difficult to identify the noise analysis as a real measurement in a training airfield. In order to overcome these practical limitations and to establish appropriate noise countermeasures, a noise map is prepared using the Integrated Noise Model Version 7.0 of the aircraft noise prediction program used by the FAA. The noise of C90GT aircraft was measured while flying the takeoff route, landing route, and long route. We want to identify areas where noise damage is more than 70 WECPNL. No area exceeding the legal standard of 70 WECPNL was found in all routes.

A Study on the Vibration of Rotordynamic System Structured Rotor-Bearing and Rotor-Bearing-Stator (로터-베어링/로터-베어링-스테이터로 구성된 회전체 진동에 관한 연구)

  • 주성현;김광식;김창호;이성철
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.173-178
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    • 1990
  • 로터-베어링축계는 증기및 가스터빈, 터보 발전기, 압축기등 거의 모든 산업 기계류에서 동력 전달의 기본 도구로써 사용되고 있다. 즉 회전에 의한 동력 의전달은 비교적 간단히 대용량의 동력을 효율적으로 전달할 수 있다. 이에 따라 회전기계류에 대한 연구는 산업 혁명 이후 꾸준히 발전되어 온바, 특히 근래에 들어와 산업기계류의 경쟁이 치열하여짐에 따라 산업기계류의 고정 밀화, 고속화, 고신뢰화 요구가 증대하고 있는 현실을 비추어 볼때, 산업 기 계류의 근간을 이루고 있는 로터-베어링 축계의 안정성을 포함한 진동에 관 한 문제는 회전기계류 설계의 주요 기술로써 연구.개발의 필요성이 매우 높 다 하겠다. 회전축계 진동 관련 연구는 두 분야로 대별될 수 있는데 언밸런 스(Unbalance)에 의한 Synchronous진동과 여러가지 원인에 의해 계의 불안 정성을 유발시키는 Nonsynchronous진동으로 나눌 수 있다. 본 연구에서는 이들 연구의 기본이 되는 회전축-베어링계 동특성 해석 프로그램을 개발하 였다. 여러가지 방법이 있으나 여기서는 Holzer가 비틀림 진동에 적용하고, Mykiestad(2)와 Prohl(3)에 의하여 회전축의 횡 진동에 적용된 이후 Lund(4) 등에 의하여 베어링의 영향등이 첨가된 전달 매트릭스 (Transfer Matrix) 방 법을 이용하여 임계속도(Critical Speed), 모우드 형태(Mode shapes)를 예측 하고 불안정 판정(Instability Criteria)등을 할 수 있는 프로그램을 개발하였 다. 특히 Murphy(1)의 다항식 방법(Polynomial Method)에 기본을 두어 기존 의 전달 매트릭스가 가지고 있던 반복, 수렴 시간 문제와 빠뜨리는 임계속도 예측에 대한 개선을 이루었으며 기존 논문과 실험 결과와의 비교 검토를 통 하여 개발된 프로그램의 신뢰성을 검토하였다. 특히, 각종 회전 기계의 소형 화, 경량화 추세에 따라 지반이나 케이싱이 경량이거나 유연하여 회전축과 동적으로 연성된 경우 회전축-베어링-지반으로 이루어진 2중구조의 회전축 계 동특성을 해석할 수 있는 프로그램을 개발하므로서 회전 기계류의 진동 전반에 걸친 문제점에 대한 그 원인과 현상을 명확히 분석하여 국내의 전기 계류의 보다 신뢰성있는 설계 및 제작자료를 확보하는데 기여할 수 있게 하 였다.

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The Development of Shipboard Noise Analysis System using Statistical Energy Analysis(I) (SEA를 이용한 선박소음해석 시스템 개발(I))

  • Hyun-J. Kang;Hyun-S. Kim;Jae-S. Kim;Sung-Y. Han;Young-C. Lee
    • Journal of the Society of Naval Architects of Korea
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    • v.31 no.1
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    • pp.133-141
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    • 1994
  • In this paper, experiences obtained during the development of MASS(Noise Analysis of Ship-board using SEA) are described. The results are summarized as follows. (1) The modelling techniques for ship structure and cabins are suggested. (2) Structureborne and airborne noise for a real ship were measured at sea trial and predicted by NASS. The differences between the two values are acceptably small for the cabins located on higher decks, although problems related with modelling of lower decks and evaluation of radiation efficiency were found.

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