Vehicle Platooning Impact on Drag Coefficients and Energy/Fuel Saving Implications

In this paper, empirical data obtained from the literature were used to develop models that capture the impact of the vehicle position in a platoon of homogeneous vehicles and the distance gap to its lead (and following) vehicle on its drag coefficient. These models are developed for light duty vehicles (LDVs), buses, and heavy duty trucks (HDTs). The models that are fit using a constrained optimization formulation are then used to extrapolate the empirical measurements to a wide range of vehicle distance gaps. The results show a significant reduction in the vehicle fuel consumption when compared with those based on a constant drag coefficient assumption. Specifically, considering a minimum time gap between vehicles of 0.5 seconds running at a speed of
$100 \; km/hr$
, the fuel reduction that is achieved is
$5 \%$
,
$17 \%$
, and
$12 \%$
for LDV, bus, and HDT platoons, respectively. For longer time gaps (gap
$\approx 2$
seconds), the bus and HDT platoons still experience fuel reductions in the order of
$8 \%$
, whereas LDVs incur negligible fuel savings.