Skin friction and dimple design: Exploring the synergistic effect of drag reduction on Ahmed body

Jeyaseelan, Risshe (2023) Skin friction and dimple design: Exploring the synergistic effect of drag reduction on Ahmed body. Project Report. Universiti Teknikal Malaysia Melaka, Melaka, Malaysia. (Submitted)

Text (Full Text) Skin friction and dimple design exploring the synergistic effect of drag reduction on Ahmed body.pdf - Submitted Version Download (1MB)

Abstract

Buses play a vital role in public transportation today. However, due to their large size, they experience significant aerodynamic drag when traveling at high speeds over long distances. This research aims to optimize the reduction of drag coefficient by introducing dimples on the top surface of an Ahmed Body, using Skin Friction approaches. The primary cause of this drag is the inefficient aerodynamic shape, resulting in the separation of the boundary layer. In particular, the separation occurring at the top of the bus contributes significantly to the high drag coefficient and skin friction. To address this issue, the Ahmed Body, a simple 3D bluff body representing a simplified car, was selected for simulation in this research (Beaudoin & Aider, 2008). A modified Ahmed Body model, resembling the actual bus geometry, was developed, and a virtual wind tunnel test was conducted to determine the benchmark drag coefficient. To mitigate the problem, the implementation of dimples on the vehicle's roof was proposed as a solution. These dimples serve to delay boundary layer separation and reduce skin friction, resulting in a lower drag coefficient. The effectiveness of this approach was evaluated through simulations using the Virtual Wind Tunnel in Ansys Fluent. Additionally, a comprehensive analysis was performed to thoroughly investigate the relationship between the drag coefficient and skin friction.

Actions (login required)

View Item