• Title, Summary, Keyword: Interior noise

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Analysis of Interior Noise of High Speed EMU by using SEA (동력 분산형 고속철도 차량의 실내소음 해석 : SEA 응용)

  • Kim, Tae-Min;Kim, Jeung-Tae;KIm, Jung-Soo
    • Proceedings of the KSR Conference
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    • pp.970-978
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    • 2010
  • In this study, interior noise of the high speed EMU was estimated by statistical energy analysis (SEA) method. Based on the data measured at a distance of 25m from a running train, exterior noise of the running train was calculated. And then it was designed as noise sources in VA ONE, a commercial software of SEA. coupling and damping loss factor of high speed EMU studied in previous studies is used. The interior noise of the train was estimated for a open-land section. The analysis of interior noise of HST in the tunnel section will be estimated through same method.

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The Source Identification of Noise Using Characteristics of Transmission and the Reduction of Interior Noise for Changing the Input Factor (전달특성을 이용한 소음원 규명과 입력요소 변경에 의한 실내소음 저감)

  • Lee, You-Yub
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.17 no.12
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    • pp.1254-1261
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    • 2007
  • The structure has several types of noise and booming noise of a vehicle is usually caused by the vibration of the vehicle's body transmitted from the engine through the mounting system. Vector synthesis analysis is performed to predict the booming noise when the characteristic of the engine mounting system is changed., i.e., when magnitudes and phases of vibratory forces after the mounts are altered. To use this method effectively, the concept of Multi-dimensional-analysis and Experimental Design are introduced to identify the contributions of each vibration sources and transmission paths to interior noise. It was used 3inputs/1output system and found the magnitudes and phases of the forces for minimizing the noise. Finally, the synthesized interior booming noise level is predicted by the vector synthesis diagram. It is shown that the vector synthesis method can be used to obtain the optimum design characteristic of the mounting system to control the interior booming noise of a vehicle.

Sound Quality Evaluation of Vehicle Interior Noise Using Virtual Sound Quality Analysis (가상 음질 분석을 이용한 자동차 실내소음 음질 평가)

  • Kang, Sang-wook
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.27 no.1
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    • pp.100-106
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    • 2017
  • Sound quality engineering in automobile noise applications has become more and more important under the current quiet driving condition because various noise components masked under high noise level can be audible in quieter driving situation. Many researches have been carried out for subjective and objective assessments on automobile sounds and noises. In particular, the interior sound quality has been one of research fields that can give high-quality feature to automobile products. Although many works related to the interior sound quality have been progressed or completed in foreign countries, limited research results are presented in the country. In the study, subjective assessments are first performed with 20 subjects to select perceptual adjectives suitable to the assessment of car interior noises during acceleration. The selected perceptual adjectives are employed as the assessment scales to evaluate the acceleration noises in questionnaire procedures using 35 subjects, for which several noises are created through digital filtering of the acceleration noises measured. Mean values and standard deviations for subjective assessment scores obtained by the questionnaire procedures are calculated and their reliability are also verified. Finally, various statistical analyses such as the correlation analysis and the factor analysis are carried out to reveal the interrelationship between the assessment scales and the spectrum components of the acceleration noises.

An interior noise characteristic analysis of Busan Metro Line 3 (부산 도시철도 3 호선 실내소음 특성분석)

  • Ahn, Chan-Woo;Hong, Do-Kwan;Han, Geun-Jo;Gang, Hyeon-Uk;Lee, Kwon-Soon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.362-367
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    • 2010
  • This paper deals with the correlation between the interior noise and the floor vibration of the train from rolling, impulse and friction in Busan Metro line 3. The correlation is verified by sound and vibration measurement causing friction between the railway and the wheel. If ANC(Active Noise Control) system can reduce 5 dB in below 500 Hz, the sound pressure level of the whole band pass can be reduced about 1.8-4.8 dB in squeal noise. Curve squeal noise is the intense high frequency tonal that can occur when a railway vehicle transverses a curve. The frequency range is from around 500 to almost 20,000 Hz, with noise levels up to about 15 dB in curve.

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Study on evaluating the interior noise about exterior noise of Apartment house (공동주택 외부소음에 대한 실내소음도 평가에 관한 고찰)

  • Park, Young Min;Kim, Kyoung Min
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.848-851
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    • 2014
  • In a small territory like South Korea, the only alternative to accommodate people in a big city is building apartment house. Exterior traffic noise is not inevitable as the apartment house is set up on wayside or main road is newly established near the area. As the request for quiet environment increases for a better quality of life recently, the exterior noise is considered to be resolved. This study shows the present condition of exterior noise of apartments and reviews a need for the improvement by comparing and analyzing the regulations of main country. Finally, considered the evaluating the interior noise in the apartment house.

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Study on Interior Noise Transfer Path Analysis by Tire Cavity Resonance (타이어 공동의 공명에 의한 차량 실내음 전달경로 연구)

  • Lee, Sang-Ju;Kang, Byun-Seok
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.129-133
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    • 2005
  • Vibration transmitted through rolling tire is a major source of road noise in vehicle interior noise on the range of low frequency.($0{\sim}500Hz$) Among various road noises, tire cavity noise has very peak on $200{\sim}250Hz$. And generally it is generated by cavity resonance of tire. In this paper, tire cut-sample is used to calculate the tire cavity frequency. Cavity resonance frequency of tire is measured through vertical/tangential forces at load cell of axle using drum cleat impact. This method is useful to find cavity peak because measured forces do not have complex peaks. And changing the test conditions (air inflation, loads), tire cavity resonance characteristics are identified. Finally, vehicle interior noise is measured as tire/vehicle are changing. As difference of tire vertical force is bigger, interior noise level is higher at cavity frequency. Also we can assume that vehicle sensitivity is important factor at tire cavity noise.

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A Study on Interior Noise Contribution Analysis of Trains based on OTPA Method (OTPA방법을 이용한 철도차량 실내 소음 기여도 분석 연구)

  • Jung, Jae-Deok;Hong, Suk-Yoon;Song, Jee-Hun;Kwon, Hyun-Woung;Noh, Hee-Min;Kim, Jun-Kon
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.26 no.1
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    • pp.97-103
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    • 2016
  • The sensitivity of interior noise that the passengers perceive is comparatively high in the train, and structure-borne and air-borne types of noises come into the train. In this paper, to analyze contributions of these noise sources operational transfer path analysis(OTPA) is used. OTPA has some advantages of executing the contribution rates of several sources simultaneously, and in this work, 29 points are measured while running. Transfer functions between reference measurement points and response measurement points are calculated by the singular value decomposition(SVD) and Principal component analysis(PCA) method, and the frequency characteristics of the noise source are successfully derived. Also the interior noise is predicted and compared with measurement data to show the reliability.

Hyundai Motor's 4th NVH open BMT - Wind noise prediction on the HSM (Hyundai simplified model) using Ansys Fluent and LMS Virtual.Lab

  • Hallez, Raphael;Lee, Sang Yeop;Khondge, Ashok;Lee, Jeongwon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.562-562
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    • 2014
  • Assessment of aerodynamic noise is becoming increasingly important for automotive manufacturers. Flow passing a vehicle may indeed lead to high interior noise level and affect cabin comfort. Interior noise results from various mechanisms including aerodynamic fluctuations of the disturbed flow around the side mirror or pillar, hydrodynamic and acoustic loading of the car panels and windows, vibration of these panels and acoustic radiation inside the vehicle. Objective of the present study is to capture these important mechanisms in a simulation model and demonstrate the ability of the combined simulation tools Fluent / Virtual.Lab to provide accurate aerodynamic and interior noise prediction results. Previous study focused on the noise generated by the turbulence around the A-pillar structure of the HSM (Hyundai simplified model). The present study also includes the effect of the side-mirror and rain-gutter structures. Complete modeling process is presented including details on the unsteady CFD simulation and the vibro-acoustic model with absorption materials. Guidelines and best practices for building the simulation model are also discussed.

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Interior noise of a KTX vehicle in a tunnel (KTX 차량의 터널 통과 시 소음특성)

  • Choi, Sung-Hoon;Kim, Jae-Chul;Lee, Chan-Woo;Cho, Jun-Ho
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.49-52
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    • 2004
  • High-speed trains with the maximum speed of 300 km/h have started revenue services since April 2004. A large portion of the 'Kyung-Bu' line is comprised of tunnels or bridges, which may cause excessive noise in a vehicle. The vibration generated by the trains propagates into the structure of the tunnel and the vehicle and it can be radiated as noise inside the vehicle interior. This noise can usually be heard as low frequency structure-borne noise. Measurement of the noise and vibration inside the KTX vehicle confirmed that the noise comprises of frequencies below 250 Hz with a couple of broad peaks.

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An application of the Statistical Energy Analysis for Absorbing and Soundproofing Materials of Vehicle (자동차용 흡.차음재의 성능분석을 위한 통계적 에너지 기법 적용의 검정)

  • Lee, Chang-Myung;Lee, Jun;Kim, Dae-Gon;Jung, Byoung-In
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.1109-1113
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    • 2001
  • Interior parts of a vehicle are getting important to reduce interior noise of car. Therefore, prior analysis of cabin noise related with interior parts are necessary at first design stage. Recently, Statistical Energy Analysis(SEA) has been suggested as a possible way for meddle of high frequency range analysis with interior parts. This article introduces an example of the application of SEA to predict air born noise of cabin of car.

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