Experimental Study of Pressure Coefficients and Flow Field Visualization on a Car Model Based on Shell Eco-marathon Competition Rules

Aerodynamic efficiency in competition vehicles is considered one of the most important aspects to achieve the best results and turns out to be a fundamental factor in reducing fuel consumption in a vehicle, as is the case with the Shell Eco-marathon Competition. Vehicle aerodynamics has a daily interest in new car prototype design in order to attempt to save fuel. Pressure forces play an important role in car fuel economy and require a detailed study. Wind tunnel experiments play an important role in the study of aerodynamic parameters. The aerodynamics around a vehicle will affect the power, economy, handling stability, and comfort during driving and fuel consumption. In this work, pressure coefficients (C_p) at midline around the car model were measured at three different flow speed wind velocities, 14 m/s, 24 m/s, and 30 m/s. Zones with high-, medium-, and low-pressure coefficients were identified on the surface of the vehicle. The low-value C_p found in this study reveals that the geometry of the car model is quite aerodynamic. However the flow visualization showed some areas with turbulence. Drag coefficient based on C_p and unit span length of the car was evaluated, this coefficient was of the order of 9 × 10⁻².