Introduction of a New Full-Scale Open Cooling Version of the DrivAer Generic Car Model

Investigation of Drag Reduction Technologies for Light-Duty Vehicles Using Surface, Wake and Underbody Pressure Measurements to Complement Aerodynamic Drag Measurements

“…However, Figure 13 shows a clear inverse relationship between the changes in average base pressure and drag coefficients due to closing the AGS, and a similar trend due to sealing the grille, with respect to the open cooling configuration. A comparable trend relating larger negative changes in base pressure with lower cooling drag has been reported in the literature [10], but only for different configurations of the same vehicle.…”

“…Sealing the external grille redirects the flow more efficiently than closing the AGS, as it reduces momentum losses due to flow entering the cavity between the grille and closed shutter surfaces, and results in a smaller area of high pressure on the front face of the vehicle. Figure 8 shows that closing and/or sealing the cooling systems significantly lowered the measured centerline base pressures of CS2 and MS2, as observed by Hupertz et al [9] for the OCDA model as well as by Pitman and Gaylard for an SUV [10], but had less to no effect on those of the CUVs, CS1 and MS1. This could explain the smaller amount of drag reduction measured for CS2 and MS2 compared to the other vehicles, as the reduction in cooling drag was somewhat countered by an increase in base drag for CS2 and MS2, whereas the cooling drag reduction technologies of some of the other vehicles may have been more effectively optimized.…”