Computational fluid dynamics simulation of drag reduction by riblets on automobile

• Main Authors: Ghazali, N.N.N., Yau, Y.H., Badarudin, A., Lim, Y.C.
• Format: Conference or Workshop Item
• Language: English
• Published: 2009
• Subjects: TA Engineering (General). Civil engineering (General)
• Online Access: http://eprints.um.edu.my/11114/1/Computational_Fluid_Dynamics.pdf; http://eprints.um.edu.my/11114/

One of the ongoing automotive technological developments is the reduction of aerodynamic drag because this has direct impact on fuel reduction, which is a major topic due to the influence on many other requirements. Passive drag reduction techniques stand as the most portable and feasible way to be implemented in real applications. One of the passive techniques is the longitudinal microgrooves aligned in the flow direction, known as riblets. In this study, the simulation of turbulent flows over an automobile in a virtual wind tunnel has been conducted by computational fluid dynamics (CFD). Three important aspects of this study are: the drag reduction effect of riblets on smooth surface automobile, the position and geometry of the riblets on drag reduction. The simulation involves three stages: geometry modeling, meshing, solving and analysis. The simulation results show that the attachment of rib lets on the rear roof surface reduces drag coefficient by 2.74%. By adjusting the attachment position of the riblets film, reduction rates between the range 0.5%-9.51% are obtained, in which the position of the top middle roof optimizes the effect. Four rib let geometries are investigated, among them the semi-hexagon trapezoidally shaped rib lets is considered the most effective. Reduction rate of drag is found ranging from -3.34% to 6.36%.