Transactions of the Korean Society of Mechanical Engineers B (대한기계학회논문집B)

The Korean Society of Mechanical Engineers (대한기계학회)
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Effects of the Air Spoiler on the Wake Behind a Road Vehicle by PIV Measurements

자동차 후류에서 에어스포일러의 영향에 대한 PIV 측정

  • 김진석 (순천대학교 대학원 기계공학과) ;
  • 성재용 (서울산업대학교 기계공학과) ;
  • 김정수 (순천대학교 기계자동차공학부) ;
  • 최종욱 (순천대학교 기계자동차공학부) ;
  • 김성초 (순천대학교 기계자동차공학부)
  • Published : 2006.02.01
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Abstract

A particle image velocimetry (PlV) technique has been applied to measure the quantitative flow field characteristics behind a road vehicle with/without an air spoiler attached on its trunk and to estimate its effect on the wake. A vehicle model scaled in the ratio of 1/43 is set up in the mid-section of a closed-loop water tunnel. The Reynolds number based on the vehicle length is $10^5$. To investigate the three-dimensional structure of the recirculation zone and vortices, measurements are carried out on the planes both parallel and perpendicular to the free stream, respectively. The results show significant differences in the recirculation region and the vorticity distributions according to the existence of the air spoiler. The focus and the saddle point, appearing just behind the air spoiler, are disposed differently along the spanwise direction. Regarding the streamwise vortices, the air spoiler produces large wing tip vortices. They have opposite rotational directions to C-pillar vortices which are commonly observed in case that the air spoiler is absent. The wing tip vortices generate the down-force and as a result, they can make the vehicle more stable in driving.

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References

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