Mathematical modelling of sedan vehicle front-end profiles for aerodynamics efficiency analysis / Afzatul Najwa Nor Azman, Kausalyah Venkatason and Shasthri Sivaguru

The study utilizes mathematical modelling and statistical analysis employing the central composite design (CCD) sampling technique to improve vehicle front-end (VFE) aerodynamics. Seven critical characteristics, including windshield angle, hood edge height, and bumper centre height, are examined for their influence on drag coefficient (Cd). The model-based calibration (MBC) toolbox in MATLAB builds a response model that captures parameter interactions and drag coefficient effects. The fitness function minimizes root mean square error (RMSE) and maximizes R-Squared (R²), yielding RMSE values of 0.0065 for Cd and R² values of 89.2%. Analysis of Variance (ANOVA) demonstrates that windshield angle and hood edge height are the most important factors affecting drag coefficient (Cd), with significant interactions with bumper centre height. Improving aerodynamic stability by refining the windshield angle, hood edge height, hood length, and bumper center height enhances safety by minimizing turbulence during vehicle operation. This study advances prior research by integrating a detailed CCD-based modelling approach with multi-parameter interaction analysis, providing a more precise and predictive framework for optimizing VFE geometry. The novelty lies in the identification and development of a vehicle front-end design that highlights the front-end design profiles that contribute to the aerodynamics efficiency. Vehicle manufacturers will be better informed on which influential parameters to tweak in the frontal design to reduce drag.