Page 38 - ATZ WORLDWIDE

DEVELOPMENT AERODYNAMICS

can slide out of the respective lateral and
upper wing. Since 2013, Betterflow has a
patent on this particular kinematics sys-
tem with multi-joint system, a detail can
be viewed in FIGURE 5, in countries both
inside and outside of the EU [6].

PRELIMINARY FUNCTIONAL MODEL

The task at the conceptual stage was to
demonstrate the fundamental function-
ality, which formed the basis for further
findings in the serial production. First,
a functional model with pneumatic
drive was designed, built and tested on
a refrigerated trailer for aerodynamic
functionality and suitability for every-
day use.
FIGURE 2 Real situation at a loading ramp (a) and detail (b): cargo doors are often very close to each other The test findings will lead to a more
with a distance of approximately 80 cm (© Betterflow, Edag) simple kinematics, drive concept and
coupling of the pivoting and sliding
movement, which are expected to signif-
icantly reduce costs and allow an overall
Since cargo doors are very close to more, these systems have weak points as more robust construction. Experiments
each other with a distance of approxi- regards aerodynamics, which are caused with the GPS automatic system have
mately 80 cm, FIGURE 2, and the driver by discontinuous flow transitions, steps shown that speed-controlled operation is
must have unobstructed rear view when and large gaps. practicable.
manoeuvring with the open door, the Different opening mechanisms have First trials on circular test tracks, on
pivot angle of the doors and the maxi- been tested and compared under techni- the highway, and by means of CFD
mum height of the closed system must cal and economic aspects. According to studies have shown that slots between
meet strict requirements. Furthermore, the test, the used multi-joint system is an the wings and the trailer need to be
the law prescribes that a closed system effective and simple kinematics option optimised by the means of sealing sys-
must not increase the height by more for shifting the wings from the stowing tems and structural transitions. To meet
than 200 mm. position into an external operating posi- the regulations for day-night marking,
The system will initially be installed tion, FIGURE 4. In this case the rear sur- the wings on the rear edges must be
as a new part during the trailer produc- face remains open at the upper edges. designed in such a way that a 50 mm
tion and will later be available as a retro- To fill it, sliding wings are used which wide reflector stripe can be attached.
fit part. Its design allows to fit it on all
common rear portals of trailer and to
easily install it as a module within a
short period of time. Insulated trailer
doors will be provided with reinforce-
ments at the factory, which will form an
insulated and load-bearing interface.
Furthermore, the energy sources such as
ones for electricity or pneumatics must
be available at the rear portal.

SPECIAL KINEMATICS
A special kinematics is required to allow
the system to lean flat against the door
in a compact folded stowing position,
FIGURE 3, and to project tangentially from
the vehicle in an operating position.
Familiar rear wing systems, which are
attached to the edges of the vehicle joints
and fold flat on the top of each other, can FIGURE 3 CAD drawing of the preliminary functional FIGURE 4 CAD drawing of the preliminary functional
model: in the operating position, the rear wing
model: the compact stowing position, the rear
easily be damaged. They do not allow wing system (light-blue and dark-blue) leans flat system shows its advantages thanks to its multi-joint
the door to be fully opened. Further- against the door (© Betterflow, Edag) system (red and yellow) (© Betterflow, Edag)
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