Investigation into effects of side-window rubber sealer on cabin interi-or noise due to external flow disturbances of vehicle

2021 ◽  
Vol 263 (2) ◽  
pp. 4361-4367
Author(s):  
Sangheon Lee ◽  
Songjune Lee ◽  
Cheolung Cheong ◽  
Hyerin Kwon ◽  
Changman Seo
Keyword(s):  
Numerical Methods ◽  
Surface Pressure ◽  
Jet Flow ◽  
External Flow ◽  
Performance Criteria ◽  
Design Stage ◽  
Sound Insulation ◽  
Wind Noise ◽  
Side Window ◽  
Insulation Performance

Electric vehicles' rapid commercialization increases the relative importance of wind noise, especially for cabin interior noise. In this study, systematic numerical methods are developed to assess the wind noise insulation performance of side-window rubber seals in a design stage. First, the simplified automotive cabin model (SACM) is constructed to test the rubber seals' sound insulation performance due to external flow disturbance generated by jet flow. The pressure signals due to the jet flow are measured inside and outside the SACM. The difference between the two signals is used as sound insulation performance criteria, so-called insertion loss (IL). Second, a numerical methodology is developed to predict the IL. The surface pressure field on the side window due to jet flow is predicted by using the high-accurate Lattice Boltzmann Method. The predicted surface pressure fluctuations are applied as input load causing side-window vibration. The interior sound is then computed by using the calculated window vibration as input. The validity of numerical methods is confirmed by comparing the predicted results with the measured ones. Finally, the present methods' ability as a design tool is confirmed by comparing the IL of the pad-added rubber seal with that of the regular seal.

Numerical Study on the Mechanism of Wind Noise Generation About a Car-Like Body

1994 ◽  
Vol 116 (3) ◽  
pp. 424-432 ◽  
Author(s):  
Ming Zhu ◽  
Yuji Hanaoka ◽  
Hideaki Miyata
Keyword(s):  
Surface Pressure ◽  
Flow Separation ◽  
Numerical Study ◽  
Pressure Fluctuations ◽  
Strong Relationship ◽  
Vortical Flow ◽  
Noise Generation ◽  
Front Side ◽  
Wind Noise ◽  
Side Window

Three-dimensional flow separation about the sharp-edged front-pillar of a car-like body at high cruising speed is numerically studied. A time-dependent and full Navier-Stokes simulation is carried out for the understanding of mechanism of wind noise generation due to the vortical flow motions. The surface pressure fluctuations on the front-side window are examined in terms of wind noise, based on a simplified Lighthill-Curle’s equation. The simulated results are validated regarding the numerical grid resolution and assessed by comparison with the conventional acoustic theory. The analyses of the simulated flow-field data indicate that there is a strong relationship between the vortical motions associated with the flow separation and the surface pressure fluctuations on the front-side window. The bifurcations of flow geometry, such as the breakdown of a separated vortex as well as the vortex-vortex interaction, seem to be most strongly related to the production of surface pressure fluctuations.

Effect of different types of ceilings on floor impact sound insulation performance in CLT model building

2021 ◽  
Vol 263 (2) ◽  
pp. 4402-4409
Author(s):  
Atsuo Hiramitsu ◽  
Susumu Hirakawa ◽  
Takahiro Tsuchimoto ◽  
Takashi Yamauchi
Keyword(s):  
Model Building ◽  
Sound Insulation ◽  
Impact Noise ◽  
Timber Construction ◽  
Stress Relieving ◽  
Measurement Results ◽  
Absorbing Material ◽  
Vibration Insulator ◽  
Effective Use ◽  
Insulation Performance

The floor impact noise generated in a building often causes problems among residents. The floor impact sound insulation performance of timber construction buildings is lower than that of concrete construction. However, due to the large supply of wood and the stress-relieving effects of wood, the use of wood is being promoted around the world. In Japan, the Act on the Promotion of the Utilization of Wood in Public Buildings was enforced to promote the use of CLT (Cross Laminated Timber) for the effective use of wood. We have been experimentally investigating the effect of floor finish structure in CLT model building. In this paper, we report the measurement results of the change in floor impact sound insulation performance when the suspended ceiling structure was changed. As results, it was confirmed that the effect of the sound-absorbing material in the ceiling cavity and the effect of the double-layer ceiling board were effective. In addition, it was clarified that the dry-type double floor structure with rubber vibration insulator on its legs is an effective floor finish structure for improvement of heavy and light weight floor impact sound insulation performances.

Effect of ceiling and dry-type double floor on heavy-weight floor impact sound in concrete building and CLT building.

2021 ◽  
Vol 263 (3) ◽  
pp. 3064-3072
Author(s):  
Takashi Yamauchi ◽  
Atsuo Hiramitsu ◽  
Susumu Hirakawa
Keyword(s):  
Frequency Band ◽  
Sound Level ◽  
Center Frequency ◽  
Sound Insulation ◽  
Octave Band ◽  
Band Center ◽  
Heavy Weight ◽  
Concrete Building ◽  
Floor Structure ◽  
Insulation Performance

The air layer between the interior finishes and the structure is used as piping and wiring space. In many cases, ceilings and dry-type double floors are commonly constructed in Japan. However, the effect of the air layer of ceilings and dry-type double floors on the heavy-weight floor impact sound insulation performance has not yet quantitatively investigated. Therefore, in this study, the same floor and ceiling structures were constructed for concrete and CLT buildings, and the heavy-weight floor impact sound was investigated. As results, it was confirmed that the reduction amount of the heavy-weight floor impact sound by the ceiling tended to be smaller in CLT buildings than in concrete buildings. However, the trends were similar. Due to the dry-type double floor structure, the heavy-weight floor impact sound level was increased in concrete building and decreased in CLT building at 63 Hz in the octave band center frequency band. Therefore, it can be said that the dry-type double floor structure can be used to improve the heavy-weight floor impact sound performance in the CLT building.

scholarly journals Sound insulation performance optimization of lightweight sandwich panels

2016 ◽  
Vol 18 (4) ◽  
pp. 2574-2586 ◽  
Author(s):  
Xiao-mei Xu ◽  
Yi-ping Jiang ◽  
Heow-pueh Lee ◽  
Ning Chen
Keyword(s):  
Performance Optimization ◽  
Sandwich Panels ◽  
Sound Insulation ◽  
Insulation Performance

Research on the Insulation Performance of Sound-Isolating and Decoupled Tiles

2013 ◽  
Vol 457-458 ◽  
pp. 703-706 ◽  
Author(s):  
De Jin Qian ◽  
Xue Ren Wang ◽  
Xu Hong Miao
Keyword(s):  
Large Scale ◽  
Acoustic Radiation ◽  
Single Point ◽  
Mechanical Vibration ◽  
Sound Insulation ◽  
Acoustic Performance ◽  
Operating Modes ◽  
Insulation Effect ◽  
Vibration And Sound Radiation ◽  
Insulation Performance

The acoustic performance of sound-isolating and decoupled tiles is studied from macroscopic and microscopic. First, the sound absorption and reverse sound insulation performance of sound-isolating and decoupled tiles is studied based on laminated media; then the acoustic decoupling materials influence on acoustic radiation of double cylindrical shell underwater is studied, using a double-layer cylindrical structure of large-scale as experimental model .There are large amount of operating modes designed in this experiment, such as all laying, partial laying, laying and so on. The results show that sound-isolating and decoupled tiles not only have the effect of weakening the absorption of reflections, but also have reverse sound insulation effect, which increases as frequency increases; for single point mechanical vibration, the tiles can effectively inhibit vibration and sound radiation of high frequency in the double shell.

scholarly journals Improvement of sound insulation performance of multilayer windows by using microperforated panel

2011 ◽  
Vol 32 (2) ◽  
pp. 79-81 ◽  
Author(s):  
Rui Lin Mu ◽  
Masahiro Toyoda ◽  
Daiji Takahashi
Keyword(s):  
Sound Insulation ◽  
Insulation Performance
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