Investigation on aerodynamic characteristics of tailing vehicle hood in a two-vehicle platoon

Abstract

Experimental and numerical methods were performed to study the hood aerodynamics of a 1:18 scale vehicle model in a two-vehicle platoon under different fixed intra spacing and dynamic intra spacing at the Reynolds number of 4.9 × 105 and 4.08 × 105 in a 1:15 scale wind tunnel. Blockage ratio was calculated to be 5.6% for experiments. The averaged and fluctuating pressures of the hood of the tailing vehicle are much higher than that of single vehicle, and stronger fluctuation occurs at the front and rear edges of hood. Pressure fluctuation over the tailing vehicle hood increases as the intra spacing diminishes but sharply declines within intra spacing of 0.2 L. The energy of fluctuation is concentrated in frequency bands from 50 to 110 Hz at wind speed of 30 m/s and 40–90 Hz at wind speed of 25 m/s. Energy at the main frequency bands and peak frequencies take up nearly 25% of total energy, respectively. The results of proper orthogonal decomposition show that total energy proportion is 49.6% for the first 11 modes and 67.0% for the first 30 modes, respectively. Relative motion at low speed has no discernible effect on hood behavior and peak frequencies have inclination to decline during the process of vehicle approaching.

Study of the Effect of Vertical Airfoil Endplates on Diffusers in Vehicle Aerodynamics

“…to create disturbances in the flow field to improve drivability [14,15]. More recent works study the aerodynamic characteristics of tailing vehicles by using commercial CFD software and particle image velocimetry experimental technique [16] and aerodynamic noise prediction [17]. Race cars are always are provided with aerodynamic devices, the diffuser being the most important element to enhance the ratio downforce vs. drag.…”

Dynamics control of topology switching for multi-functional unmanned ground vehicle platoon with VCBDL topology

“…Some new control methods have been utilized in this area. [1][2][3][4][5] For different traffic scenarios, Sawant and Chaskar developed a non-linear disturbance observerbased sliding mode control method to alleviate the peaking of control input. 6 Shojaei proposed a new control method for multiple Ackermann steering vehicle formation by combining an adaptive neural network robust controller.…”