Computational Analysis of Pitch Sensitivity for a Concept Race Car 2022-01-5065

The present numerical study investigates the design and analysis of a concept model Le Mans Grand Touring Prototype (LMGTP) car. Through analysis, aerodynamic pitch sensitivity and related factors are found to be detrimental to the straight-line stability of these high-speed race cars. Simulations are carried out on a commercial Computational Fluid Dynamics (CFD) tool for varying pitch angles of the car from −1° to +2.5°. For each pitch angle, steady-state pressure contours, velocity contours, and streamlines are presented. Additionally, coefficients and force values of lift and drag are calculated with the k-omega turbulence model implemented. Obtained numerical results are validated via Ahmed Body studies reported in the literature, and an average error deviation of 1.013% is exhibited. It is observed that lift force at the front axle increases with increasing pitch angles, leading to reduced pitch stability. At a peak of 2.5° pitch angle, the destabilizing lift force peaks at 1872 N, with the trend showing potential for front axle liftoff. The obtained results are validated with the aerodynamic stability derivative using MATLAB Simulink. A strong correlation is observed for CFD results with respect to theoretical aerodynamic pitch stability derivative calculations with peak nose-up conditions (+2.5°) indicating the highest levels of instability.