Validation of Truck Platoon Slipstream Effects

Abstract

Due to slipstream effects, platooning leads to a significant decrease of the fuel consumption of the heavy-duty vehicles (HDV). Measurements with a platoon consisting of three vehicles were performed at the Zalazone proving ground. The goal of these measurements was to get the static pressure at the front and the rear of the second vehicle to calibrate computational fluid dynamics simulation and to measure the fuel consumption directly. Measurements were done at a vehicle speed of 80 km/h and varying inter-vehicle distances. Platooning leads to a reduction of the pressure coefficients in the centre of the HDV front and an increase of the pressure coefficient at the top and the rear of the HDV. Furthermore, a reduction of the fuel consumption of the leading vehicle of 7.9% at an inter-vehicle distance of 6 m and 3.7% at a distance of 22 m was determined. A comparison to CFD simulation showed a similar fuel reduction for an inter-vehicle distance of 6 m and 22 m. CFD simulation showed an increase of fuel consumption at an inter-vehicle distance of 15 m. This increase was experimentally not validated. Also, results for the following vehicle are presented.

Experimental Investigation of the Influence of NO on a PEM Fuel Cell System and Voltage Recovery Strategies

“…On-road measurements performed in [12] report an average concentration of 241 ppb NO on an Austrian highway, with a temporary maximum of 3.2 ppm NO on the highway due to a passing vehicle and 1 ppm NO in a highway tunnel. The samples were taken close to the front number plate of the test vehicle.…”

“…Reference [13] also refers to on-road concentration measurements performed on a German highway, stating that a fuel cell vehicle would be exposed to concentrations of 219 ppb in urban areas and up to 2 ppm in traffic jams or tunnels. Reference [12] derived a NO-to-NO 2 ratio during the on-road tests of 5:1. When fuel cells are operated in special locations, such as mines, the NO concentrations can exceed the road measurements and reach up to 25 ppm [14].…”