Computational Fluid Dynamics Analysis of Aerodynamic Characteristics on Overtaking Vehicles in Crosswind Conditions

M Syafiq; Izuan Amin Ishak; Mohammad  Arafat; Razlin  Abd Rashid; Nurnida Elmira Othman; Zuliazura Mohd Salleh; Shaiful Fadzil Zainal Abidin

doi:10.15282/ijame.22.2.2025.10.0947

Authors

M. Syafiq Faculty of Engineering Technology, University of Tun Hussein Onn Malaysia, Education Hub, Pagoh, 84600, Johor, Malaysia
I. A. Ishak Faculty of Engineering Technology, University of Tun Hussein Onn Malaysia, Education Hub, Pagoh, 84600, Johor, Malaysia
M. Arafat Faculty of Engineering Technology, University of Tun Hussein Onn Malaysia, Education Hub, Pagoh, 84600, Johor, Malaysia
R. A. Rashid Department of Chemical Engineering, The University of Manchester, Manchester, M13 9PL, UK
N. E. Othman School of Mechanical Engineering, College of Engineering, Universiti Teknologi MARA, 40450 Shah Alam, Selangor, Malaysia
Z. M. Salleh Faculty of Mechanical Engineering, Universiti Tun Hussein Onn Malaysia, Persiaran Tun Dr. Ismail, 86400 Parit Raja, Johor, Malaysia
S. F. Z. Abidin Faculty of Engineering Technology, University of Tun Hussein Onn Malaysia, Education Hub, Pagoh, 84600, Johor, Malaysia

DOI:

https://doi.org/10.15282/ijame.22.2.2025.10.0947

Keywords:

Overtaking maneuver, Crosswind, Aerodynamic loads, Flow structure, Vortex generation, CFD

Abstract

Drivers frequently adjust their path due to crosswinds and overtaking, where adjacent vehicles significantly alter airflow. This study uses computational fluid dynamics to analyze the aerodynamic impact of overtaking maneuvers on simplified car models (Ahmed Bodies) under crosswind conditions. The investigation focuses on how drag, lift, and side force coefficients change during different overtaking stages at varying crosswind angles (0°, 15°, 30°, and 45°). The study focused on 2 Ahmed Body models, which are overtaking vehicle(A) and overtaking vehicle(B), in 5 different cases: before overtake, initiation of overtake, mid-overtake, completion of overtake, and after overtake. Results show that at a 15° crosswind, Car A has a higher drag coefficient (C_d: 0.3916), reducing performance and stability. At 30°, Car A shows a high lift coefficient (C_l: 0.9881); at 45°, Car B experiences a significant increase in side force coefficient (C_s: 3.1192). This is due to the pressure contour at the front corner of the vehicle surface and the vortex formation on the leeward side of the vehicles as yaw angles rise. Results show that crosswinds significantly increase aerodynamic forces and alter flow structures around vehicles. Specifically, the relative position of vehicles during overtaking greatly influences these forces, affecting vehicle stability.

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