• Title/Summary/Keyword: Buffeting Noise

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Benchmark Test of CFD Software Packages for Sunroof Buffeting in Hyundai Simplified Model (차량 썬루프 버페팅 현상에 대한 전산 해석 소프트웨어의 예측 성능 벤치마크 연구)

  • Cho, Munhwan;Oh, Chisung;Kim, HyoungGun;Ih, Kang-duck
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.24 no.3
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    • pp.171-179
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    • 2014
  • Sunroof buffeting is one of the most critical issues in the vehicle wind noise phenomena. The experimental approach to solve this issue typically requires a lot of time and resources. To reduce time and cost, the numerical approach could be taken, which can also privide more insights into physical phenomena involved in sunroof buffeting, only if the accuracy in its predictions are guranteed. The benchmark test of various numerical solvers is carried out for the buffeting behavior of a simplified vehicle body, the Hyundai simplified model(HSM). The results of each solver are compared to the experimental measurements in a Hyundai aeroacoustic wind tunnel(HAWT) at various wind speeds. In particular, acoustic response tests were performed and the results were provided prior to all simulations in order to consider the real world effects that could introduce discrepancies between the numerical and experimental approaches. Through this study, most solvers can demonstrate an acceptable accuracy level for actual commercial development and high precision experimental data and computational prediction priories can be shared in order to promote the numerical accuracy level of each numerical solver.

Flow-induced Vibration Analysis of Bridge Girder Section (교량 구조물의 유체유발 진동해석)

  • Park, Seong-Jong;Kwon, Hyuk-Jun;Lee, In;Han, Jae-Heung
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.14 no.5
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    • pp.402-409
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    • 2004
  • Numerical analysis of static and dynamic wind effects on civil engineering structures was performed. Long-span suspension bridges are flexible structures that are highly sensitive to the action of the wind. Aerodynamic effect often becomes a governing factor in the design process of bridges and aeroelastic stability boundary becomes a prime criterion which should be confirmed during the structural design stage of bridges because the long-span suspension bridges are prone to the aerodynamic instabilities caused by wind. If the wind velocity exceeds the critical velocity that the bridge can withstand, then the bridge fails due to the phenomenon of flutter. Buffeting caused by turbulence results in structural fatigue, which could lead to the failure of a bridge. Navier-Stokes equations are used for the aeroelastic analysis of bridge girder section. The aeroelastic simulation is carried out to study the aeroelastic stability of bridges using both Computational Fluid Dynamic (CFD) and Computational Structural Dynamic (CSD) schemes.

COMPUTATIONAL ANALYSIS ON DRONE NOISE OF AN AUTOMOBILE WITH OPENED REAR WINDOW (자동차 뒷 창문 개방에 의한 공명소음 전산해석 연구)

  • Bai, I.H.;Moon, Y.J.
    • Journal of computational fluids engineering
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    • v.18 no.2
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    • pp.26-34
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    • 2013
  • In modern days, automobiles are the most important means of transportation. With the development of automobiles, noises generated during operation has been recognized as a significant factor of performance to provide drivers with better driving environment along with other passengers. In this study, drone noise(pulsating noise), generated at the rear window when its opened, is predicted to understand the physics of its phenomenon at various velocities. The compressible Navier-stokes equation will be used with $6^{th}$ order compact finite difference scheme to analyze the characteristics.

Analysis of flow characteristics around the sunroof opening variation with sunroof deflector angle (썬루프 디플렉터 각도에 따른 썬루프 개구부 주변 유동 특성 연구)

  • Lee, Sung Won;Shin, Seongryong;Choi, Eui Sung;Yi, Juwan
    • The Journal of the Acoustical Society of Korea
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    • v.37 no.5
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    • pp.285-291
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    • 2018
  • In the present study, flow characteristics and wind noises around the sunroof opening are analyzed variation with panoramic sunroof deflector angle. A mesh deflector is attached to reduce wind noise while a car is driving with the panoramic sunroof opening. A new forward inclined type deflector was invented to improve wind noise. The effect of this new concept of mesh deflector on the open-panoramic flow characteristics and wind noises were studied with CAT (Computer Aided Test) and wind tunnel test, which shows the reduction of open-panoramic wind noises such as sunroof buffeting, sunroof booming, and turbulent noise. Therefore, the forward inclined type deflector can efficiently improve wind noise with the same production cost.