Investigation on the Aerodynamic Drag Reduction of the Frontal Projection of a Car using Finite Volume Method

Abstract

Aerodynamic drag significantly influences vehicle fuel efficiency and energy consumption, particularly at highway operating conditions. While full three-dimensional (3D) simulations are widely employed in automotive aerodynamics, computationally efficient two-dimensional (2D) approaches remain valuable for early-stage design screening. This study investigates the influence of windshield inclination angle on aerodynamic drag characteristics of four simplified vehicle profiles, namely MPV, Hatchback, Sedan, and Sports car configurations, using Computational Fluid Dynamics (CFD) based on the Finite Volume Method (FVM). The models were developed in CATIA V5R20 and simulated using ANSYS Fluent with Reynolds-Averaged Navier–Stokes (RANS) equations employing the standard k–ε turbulence model. The MPV served as the datum model for comparative analysis. Results demonstrate a clear inverse relationship between windshield angle and drag coefficient, where the Sports car configuration achieved the lowest drag coefficient compared to the MPV model. Flow visualization through pressure contours and velocity streamlines confirms improved flow attachment and reduced wake formation for lower windshield angles. Although absolute drag values differ from real 3D vehicle data due to geometric simplifications, the trend agrees with established aerodynamic principles reported in literature. The findings highlight the importance of frontal geometry optimization in early-stage automotive design and validate the applicability of CFD screening for comparative aerodynamic assessment.