Abstract
The purpose of this study is to examine the effect of the steady airflow field of a rear spoiler on the coefficients of drag (CD) and downforce (CDF). The type of spoiler is suggested as a two-jointed arm model that mimics the flapping flight mechanism of the Canada goose. Computational fluid dynamics (CFD) technique was used for the steady airflow analysis of a vehicle implemented with various spoiler topologies. We evaluated CD and CDF due to the three types of airfoils and the five phases of each airfoil. We obtained the following conclusions from the results: (1) We found that the best cases for CD and CDF were the case of Phase 5 and symmetry airfoil, and the case of Phase 1 and reverse airfoil, respectively. (2) It is clear that CD becomes the largest at Phase 1 of the reverse airfoil, since the eddy magnitude at the rear of the vehicle is the largest, and CDF also becomes the largest during that phase, since the pressure distribution on the upper surface of the spoiler is very large. (3) As Phase 1 moves to Phase 5 in the same type of airfoil, it is advantageous for CD and disadvantageous for CDF, respectively.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
ANSYS Fluent Version 14.0. (2011). Computer Software. ANSYS, Inc.
Bailey, F. R. and Simon, H. D. (1992). Future directions in computing and CFD. 10th Applied Aerodynamics Conf., 149–60.
Callister, J. R. and George, A. R. (1998). ‘Wind Noise’ Aerodynamics of Road Vehicles. 4th edn. SAE Int. Warrendale, Pennsylvania, USA.
Gilhaus, A. and Hoffmann, R. (1998). ‘Directional Stability’ Aerodynamics of Road Vehicles. 4th edn. SAE Int. Warrendale, Pennsylvania, USA.
Han, T., Sumantran, V., Harris, C., Kuzmanov, T., Huebler, M. and Zak, T. (1996). Flow-field simulations of three simplified vehicle shapes and comparisons with experimental measurements. SAE Trans., 106, 820–835.
Hucho, W. H. (1998). Aerodynamics of Road Vehicles. 4th edn. SAE Int. Warrendale, Pennsylvania, USA.
Jowsey, L. and Passmore, M. (2010). Experimental study of multiple-channel automotive underbody diffusers. Proc. Inst. Mech. Eng. D: J. Automob. Eng. 224, 7, 865–879.
Katz, J. (2006). Aerodynamics of race cars. Annu. Rev. Fluid Mech., 38, 27–63.
Kim, S.-E., Choudhury, D. and Patel, B. (1999). Computations of complex turbulent flows using the commercial code fluent. ICASE/LaRC Interdiscip. Ser. Sci. Eng., 7, 259–276.
Lee, Y. B. (2004). An Effective Robust Optimal Design Method for Engineering Systems with Numerical Noise. M. S. Thesis. Hanyang University. Seoul.
Liu, T., Kuykendoll, K., Rhew, R. and Jones, S. (2004). Avian wings. 24th AIAA Aerodynamic Measurement Technology and Ground Testing Conf.
Nakashima, T., Tsubokura, M., Nouzawa, T., Nakamura, T., Zhang, H. and Oshima, N. (2008). Large-eddy simulation of unsteady vehicle aerodynamics and flow structures. Proc. 6th Int. Colloquium on BBAA, 447–450.
Shih, T.-H., Liou, W. W., Shabbir, A., Yang, Z. and Zhu, J. (1995). A new keddy viscosity model for high Reynolds number turbulent flows. Comput. Fluids 24, 3, 227–238.
Tsubokura, M., Kobayashi, T., Nakashima, T., Nouzawa, T., Nakamura, T., Zhang, H., Onishi, K. and Oshima, N. (2009). Computational visualization of unsteady flow around vehicles using high performance computing. Comput. Fluids 38, 5, 981–990.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Kim, S.C., Han, S.Y. Effect of steady airflow field on drag and downforce. Int.J Automot. Technol. 17, 205–211 (2016). https://doi.org/10.1007/s12239-016-0020-2
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12239-016-0020-2