• International Journal of Automotive Technology
• /
• 제8권1호
• /
• pp.67-73
• /
• 2007

This study analyzes the interior noise that is generated during acceleration of a passenger car in terms of car body structure and panel contribution. According to the transfer method, interior noise is classified into structure-borne noise and air-borne noise. Structure-borne noise is generated when the engine's vibration energy, an excitation source, is transferred to the car body through the engine mount and the driving system and the panel of the car body vibrates. When structure-borne noise resonates in the acoustic cavity of the car interior, acute booming noise is generated. This study describes plans for improving the car body structure and the panel form through a cause analysis of frequency ranges where the sound pressure level of the rear seat relative to the front seat is high. To this end, an analysis of the correlation between body attachment stiffness and acoustic sensitivity as well as a panel sensitive component analysis were conducted through a structural sound field coupled analysis. Through this study, via research on improving the car body structure in terms of reducing rear seat noise, stable performance improvement and light weight design before the proto-car stage can be realized. Reduction of the development period and test car stage is also anticipated.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2000년도 추계학술대회 논문집
• /
• pp.157-164
• /
• 2000

This study is about predicting the interior pressure level of the korean high speed train using ray acoustic method. The motor car and the motor and passenger cabin are investigated under the environment of passing open countryside and inside tunnel of 350 km/hr. Calculated sound levels are compared with the proposed sound levels and suggestions about the transmission Joss values of isolating panels inside motor car and the guide lines of allowed sound power limit of motor equipments are provided. Results of TPI car show calculated interior sound level is below the proposed values for both cases of open countryside running and inside tunnel. Since ray acoustic method calculated only air borne noise component, real sound level of the motor car may be higher than prediction. Passenger cabins of TMI, TM5 show higher sound level than the proposed values, so window method was carried out to find the contribution of each panel components and point out the remedy of transmission path. Reduction of sound power of motor equipments should be condisered at the same time.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2008년도 춘계학술대회 논문집
• /
• pp.1114-1118
• /
• 2008

In previous fire accident of railway car, the fatality was relatively high by toxic gas poisoning cause of closed space. So the necessity of quantifying toxic gas in combustion gas was recognized and then, FT-IR spectroscopy was introduced for real-time analysis of mixed gases and stimulated analysis of the concentration of several gases. Thus, in this study, absorption bands using FT-IR were obtained by each component of combustion gases for interior materials of railway car such as flooring materials and moquette seat. And then the sample spectra were compared with the spectra of NO, $NO_2$, $SO_2$ reference gases, we could obtain some identical peaks of them.

• 한국음향학회:학술대회논문집
• /
• 한국음향학회 1994년도 FIFTH WESTERN PACIFIC REGIONAL ACOUSTICS CONFERENCE SEOUL KOREA
• /
• pp.854-859
• /
• 1994

As powertrain noise is better and better controlled, road noise inputs become more important. The interior road noise of a car is mainly induced by the wheels rolling over the road surface. Each of the four wheels act as an independent and uncorrelated excitation input. To rank the energy transfer form each input to the interior, a Transfer Path Analysis (TPA) needs to be made-which requires operational vibration measurements. However due to the multiple uncorrelated inputs, phase relations vary continuously. It is therefore necessary to separate the operational data into set of "independent phenomena" by means of a Principal Component Analysis (PCA). A TPA can then be carried out for each independent phenomenon. Operational deflection shapes referenced to these principal components share the physical phenomena. The details of the methodology are discussed and a discussion of the results on a car shows that the method gives accurate results for full vehicle testing.e testing.

• 분석과학
• /
• 제24권4호
• /
• pp.290-297
• /
• 2011

현재 자동차 실내공기질을 평가하는 방법이 ISO, 중국, 일본에서 개발 중에 있으며, 우리나라에서도 관리기준이 2010년 7월 1일 이후 생산한 신규제작자동차부터 적용되고 있다. 자동차 실내공기질을 관리하기 위해서는 자동차 실내의 내장부품으로부터 방출되는 휘발성 유기화합물을 평가하는 것이 중요하다. 이 연구에서는 모듈단위부품인 도어트림 모듈의 구성부품인 도어트림 암레스트를 ISO 12219-5방법에 따라 완제품을 평가 하였으며, ISO 12219-3방법으로 절단부품과 도어트림 구성소재를 평가하였다. Tenax TA가 충진된 스테인리스 튜브를 이용하여 VOC를 채취하여 TD-GC/MS를 이용하여 분석하였다. 두 시험방법을 비교한 결과 도어트림 암레스트로부터 방출되는 물질의 비율이 차이가 있음을 확인하였고, 도어트림 암레스트의 소재를 평가한 결과 PP substrate과 adhesive가 도어트림 암레스트에서 주요 방출원인 소재로 나타났다.

• 대한기계학회논문집
• /
• 제17권7호
• /
• pp.1833-1840
• /
• 1993

An efficient vibration analysis method, Component Mode Synthesis(CMS), for an exhaust system with bellows is presented. Analyses are performed for two types of bellows, where characteristics of vibration modes affecting idle shake and interior noise of a vehicle are examined. Also analyzed are the contributions of an exhaust and engine mounting system to the idle shake and interios noise. Comparison between the analysis and test is in good agreement, hence the CMS method is shown to be efficient and valid.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2013년도 추계학술대회 논문집
• /
• pp.291-291
• /
• 2013

The interior vehicle noise due to the exterior aerodynamic field is an important topic in the acoustic design of a car. The air flow detached from the A-pillar and impacting the side windows are of particular interest as they are located close to the driver / passenger and provides a lower insulation index than the trimmed car body parts. HMC is interested in the numerical prediction of this aerodynamic noise generated by the car windows with the final objective of improving the products design and reducing this noise. The methodology proposed in this paper relies on two steps: the first step involves the computation of the exterior flow and turbulence induced non-linear acoustic field using the CAA(Computational aeroacoustics) solver CAA++. The second step consists in the computation of the vibro-acoustic transmission through the side window using the finite element vibro-acoustic solver Actran. The internal air cavity including trim component are included in the simulation. In order to validate the numerical process, an experimental set-up has been created based on a generic car shape. The car body includes the windshield and two side windows. The body is made of aluminum and trimmed with porous layers. First, this paper describes the method including the CAA and the vibro-acoustic models, from the boundary conditions to the different components involved, like the windows, the trims and the car cavity is detailed. In a second step, the experimental set-up is described. In the last part, the vibration of the windshield and windows, the total wind noise level results and the relative contributions of the different windows are then presented and compared to measurements. The influence of the flow yaw angle (different wind orientation) is also assessed.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2014년도 추계학술대회 논문집
• /
• pp.569-569
• /
• 2014

The interior vehicle noise due to the exterior aerodynamic field is an important topic in the acoustic design of a car. The air flow detached from the A-pillar and impacting the side windows are of particular interest as they are located close to the driver / passenger and provides a lower insulation index than the trimmed car body parts. This paper presents a numerical analysis method for a simplified vehicle model. The internal air cavity including trim component are included in the simulation. The car body includes the windshield and two side windows. The body is made of aluminum and trimmed with porous layers. The methodology proposed in this paper relies on two steps: the first step involves the computation of the exterior flow and turbulence induced non-linear acoustic field using CFD Code. The second step consists in the computation of the vibro-acoustic transmission through the window using the finite element vibro-acoustic solver Actran.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2006년도 춘계학술대회논문집
• /
• pp.1437-1442
• /
• 2006

The international competition in car markets has continuously required the research about the sound quality of a car. The domestic carmakers have also invested a lot of money for the research and development of interior sound quality of passenger cars. Therefore, the aim of this research is to predict the customer's evaluation of a new vehicle. There are two major research works to achieve this goal in this research. The first one is to search questionnaires about the sound quality, which customers prefer, to identify the relationship between these questionnaires and sound metrics that is a psychoacoustics parameters, and to development sound indexes for the questionnaires. All tests for this work is proceed on the road test during acceleration. The second one is to balance the sound component (engine noise, booming noise, road noise and wind noise) of a passenger. This wok will be tested on the constant speed. All of research results will be contributed to the development of brand sound quality of a new passenger car.

• 한국산업정보학회논문지
• /
• 제9권3호
• /
• pp.71-79
• /
• 2004

자동차의 급격한 증가로 인하여 교통 정체현상이 날로 심해짐에 따라 운전자에게 보다 안전하고 쾌적한 운전 편의성을 제공하기 위한 방법으로 차량항법장치(CNS)가 제안되었으며, 최근에 출시되는 많은 차량에 카 네비게이션 시스템이 장착되고 있다. 또한 네비게이션 시스템이 단순한 차량 항법 장치로서의 위치를 넘어 차량 내 멀티미디어 시스템으로서의 기능을 감당하고 있으며, 이에 따라 자동차 내장(Interior)의 중요한 부품으로 인식되고 있다. 따라서 기능뿐만 아니라 사용성과 외형적 디자인 역시 소비자의 취향에 맞게 설계되어질 필요성이 있다. 본 연구에서는 자동차 내장 부품의 구성 요소로서의 카 네비게이션 시스템에 대하여 소비자들이 요구하는 감성요소가 무엇인지 파악해 보았다. 특히, 소비자들이 선호하는 차종에 따라 내장 부품의 감성 특성 역시 변화될 수 있으므로 차량 선호도에 기초하여 감성요소 분석을 실시하였으며, 소비자 특성별 감성 선호도 도출 기법으로서 다차원 척도법(MDS)기법의 효용성을 입증해보았다. 정통적인 세단 형태의 차종을 선호하는 사람의 경우, 네비게이션 시스템에 대하여 고급감, 조화감, 재질감을 요구하였으며, 스포츠카를 선호하는 사람의 경우는, 팬시감, 개성감, 역동감을, SUV와 MPV를 선호하는 사람의 경우는 견고감과 역동감, 편의감을 중요시하는 것으로 분석되었다.