Advertisement

Journal of Visualization

, Volume 20, Issue 2, pp 369–378 | Cite as

Drag-reducing underbody flow of a heavy vehicle with side skirts

Regular Paper
  • 226 Downloads

Abstract

Aerodynamic drag reduction in heavy vehicles is a very interesting research topic that is relevant for both the industries and the environment. The underbody flow induces considerable drag as it passes through the underside of heavy vehicles and interacts with rolling wheels and other underbody structures. Nonetheless, the drag caused by such an underbody flow has received less research attention, compared with those attributed to forebody and base body flows. Side skirts are one of the most effective drag-reduction devices to control the underbody flow. They consist of straight panels curtaining the space between the front and rear wheels. However, the mechanisms of underbody flow modified by side skirts have yet to be fully understood. In this study, the drag reduction underbody flow of a scaled-down 15-ton truck model attached with two different types of side skirts was quantitatively visualized through wind tunnel tests. Results show that the straight-type side skirt and the flap-type side skirt significantly change the flow structures under the vehicle model, reducing drag coefficient by 3.1 and 6.1 %, respectively. Furthermore, flow characteristics in the underbody of the vehicle model with and without side skirts are investigated using a PIV technique to understand the associated drag-reduction mechanism.

Graphical abstract

Keywords

Drag reduction Heavy vehicle Side skirt Flow visualization PIV Underbody flow 

Notes

Acknowledgments

This study was conducted as the second year research of the development of aerodynamic technologies for efficient road freight transport, supported by the KAIA in the Ministry of Land, Infrastructure and Transport. (NTIS 1615007940).

References

  1. Ahmed S, Ramm G, Faltin G (1984) Some salient features of the time-averaged ground vehicle wake. SAE technical paper, no. 840300Google Scholar
  2. Ahmed S, Gawthorpe R, Mackrodt PA (1985) Aerodynamics of road-and rail vehicles. Veh Syst Dyn 14:319–392CrossRefGoogle Scholar
  3. Choi H, Lee J, Park H (2014) Aerodynamics of heavy vehicles. Annu Rev Fluid Mech 46:441–468MathSciNetCrossRefMATHGoogle Scholar
  4. Cooper KR (2003) Truck aerodynamics reborn-lessons from the past. SAE Trans 112:132–142Google Scholar
  5. Cooper KR, Leuschen J (2005) Model and full-scale wind tunnel tests of second-generation aerodynamic fuel saving devices for tractor-trailers. SAE technical paper, no. 2005-01-3512Google Scholar
  6. Gerrard J (1966) The mechanics of the formation region of vortices behind bluff bodies. J Fluid Mech 25:401–413CrossRefGoogle Scholar
  7. Han T, Sumantran V, Harris C, Kuzmanov T, Huebler M, Zak T (1996) Flow-field simulations of three simplified vehicle shapes and comparisons with experimental measurements. SAE Trans 106:820–835Google Scholar
  8. Hucho WH, Sovran G (1993) Aerodynamics of road vehicles. Annu Rev Fluid Mech 25:485–537CrossRefGoogle Scholar
  9. Hwang BG, Lee S, Lee EJ, Kim JJ, Kim M, You D, Lee SJ (2016) Reduction of drag in heavy vehicles with two different types of advanced side skirts. J Wind Eng Ind Aerodyn 155:36–46CrossRefGoogle Scholar
  10. Kapadia S, Roy S, Vallero M, Wurtzler K, Forsythe J (2004) Detached-eddy simulation over a reference Ahmed car model. In: Direct and large-eddy simulation V, pp 481–488Google Scholar
  11. Krajnović S, Davidson L (2005) Influence of floor motions in wind tunnels on the aerodynamics of road vehicles. J Wind Eng Ind Aerodyn 93:677–696CrossRefGoogle Scholar
  12. Ortega JM, Salari K (2004) An experimental study of drag reduction devices for a trailer underbody and base. AIAA paper, no. 2004-2252Google Scholar
  13. Storms BL, Satran DR, Heineck JT, Walker S (2004) A study of reynolds number effects and drag-reduction concepts on a generic tractor-trailer. AIAA paper, no. 2004-2251Google Scholar
  14. Strachan R, Knowles K, Lawson N (2007) The vortex structure behind an Ahmed reference model in the presence of a moving ground plane. Exp Fluids 42:659–669CrossRefGoogle Scholar
  15. Verzicco R, Fatica M, Iaccarino G, Moin P, Khalighi B (2002) Large eddy simulation of a road vehicle with drag-reduction devices. AIAA J. 40:2447–2455CrossRefGoogle Scholar
  16. Vino G, Watkins S, Mousley P, Watmuff J, Prasad S (2005) Flow structures in the near-wake of the Ahmed model. J Fluids Struct 20:673–695CrossRefGoogle Scholar
  17. West G, Apelt C (1982) The effects of tunnel blockage and aspect ratio on the mean flow past a circular cylinder with Reynolds numbers between 104 and 105. J Fluid Mech 114:361–377CrossRefGoogle Scholar
  18. Wood RM (2006) A discussion of a heavy truck advanced aerodynamic trailer system. In: 9th international symposium on heavy vehicle weights dimensions, University Park, PA, USAGoogle Scholar

Copyright information

© The Visualization Society of Japan 2016

Authors and Affiliations

  1. 1.Department of Mechanical EngineeringPohang University of Science and Technology (POSTECH)PohangSouth Korea

Personalised recommendations