In platooning, multiple vehicles travel in close succession with very short distances between them using a technical control system (“electronic drawbar”). The vehicles are networked with each other, so that only the lead vehicle is actively driven. The following vehicles follow the lead vehicle automatically. Assistance systems take over speed control, distance maintenance, lane keeping, as well as braking and acceleration of the following vehicles.
Why is this relevant?
The technology holds enormous potential for greater sustainability in freight transport.
Environmentally friendly:
- Driving in the slipstream saves energy due to reduced air resistance.
- Reduced fuel consumption and thus increased vehicle range.
- Lower CO₂ emissions for the following vehicle; even the lead vehicle saves energy.
Safer traffic:
- Immediate, automated braking through assistance systems
- The risk of rear-end collisions is significantly reduced.
Efficient transport:
- More effective use of roads, which optimizes freight transport and reduces traffic congestion as well as travel times.
- Drivers are relieved and can focus on other tasks.
The aerodynamics behind the platoon.
In platooning, several trucks travel in close succession with very short distances between them. The following vehicles are positioned in the slipstream of the vehicle ahead and utilize the altered flow conditions behind the lead vehicle. But what exactly happens in this process?
Behind a single truck, a so-called “dead water region” forms—an area in which the air (or fluid particles) barely moves with the main flow. It is created by the separation of the flow at the rear of the vehicle (see Figure 2). The air vortices roll up into an unstable ring vortex and lose part of their kinetic energy, i.e., their velocity. At the same time, the pressure at the vehicle’s rear decreases, which increases the flow resistance. This phenomenon occurs in the so-called wake region, directly behind the vehicle.
When several trucks travel very close together—in a platoon—this flow pattern changes significantly: The wake region of the front vehicle becomes smaller, the pressure at its rear increases, and less energy is lost. This reduces air resistance. The middle and rear vehicles also experience less dynamic pressure at the front. They do not have to drive against a “wall of stationary air” but encounter an already moving airflow in the direction of travel—the slipstream effect takes hold. This leads to reduced energy consumption.
Summary:
In platooning, physical effects of fluid mechanics are deliberately utilized to reduce energy consumption in freight transport—efficiently, sustainably, and safely.
Interactive Exhibit: Try Truck Platooning Yourself!
In this virtual exhibit, you can explore the principle of platooning in an interactive way. Select one of four driving speeds, vary the distance between vehicles, and observe the resulting energy savings in real time.
Additionally, the airflow around the platoon is visualized, allowing you to directly observe the physical effects.
Try it out and experience how modern vehicle networking contributes to more sustainable freight transport!
