A Numerical Investigation of Inter-Vehicle Spacing on Aerodynamic Drag Using a Two-Dimensional Ahmed Body Model

Ahmadabadi Asle Alamdari, Ata; Chehrmonavari, Hamed; Kakaee, Amirhasan

doi:10.22068/ase.2026.734

Volume 16, Issue 1 (3-2026) ASE 2026, 16(1): 4966-4979 | Back to browse issues page

‎ 10.22068/ase.2026.734

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Ahmadabadi Asle Alamdari A, Chehrmonavari H, Kakaee A. A Numerical Investigation of Inter-Vehicle Spacing on Aerodynamic Drag Using a Two-Dimensional Ahmed Body Model. ASE 2026; 16 (1) :4966-4979
URL: http://ase.iust.ac.ir/article-1-734-en.html

A Numerical Investigation of Inter-Vehicle Spacing on Aerodynamic Drag Using a Two-Dimensional Ahmed Body Model

Ata Ahmadabadi Asle Alamdari

, Hamed Chehrmonavari

, Amirhasan Kakaee

Abstract: (995 Views)

This study employs two-dimensional CFD simulations to analyze how rear slant angle and inter-vehicle spacing dictate aerodynamic drag in a tandem Ahmed body configuration. We systematically evaluated slant angles from 15° to 45° and longitudinal spacings from X/L = 0.1 to 0.5. The results delineate three distinct aerodynamic regimes for the trailing vehicle: a drafting zone at close distances (X/L=0.1) with significantly reduced drag, an interference zone (X/L=0.2-0.3) where drag peaks, and an independence zone (X/L>0.4) where vehicles behave aerodynamically isolated. Furthermore, the model successfully captures the critical drag rise as the slant angle surpasses 30°, a key flow transition. While the simulation over-predicts absolute drag values, which is an expected outcome of the 2D approach, it demonstrates high fidelity in capturing complex trends, providing foundational insights for optimizing vehicle platooning strategies.

Keywords: Ahmed Body, Inter-Vehicle Spacing, Drag Coefficien, t Wake Interaction, Y⁺ distribution, CFD

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Type of Study: Research | Subject: Vibration, noise, Acoustic