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the qualified development and validation has been tested in the real traffic situa-
process. tions. The following measurements have
In the course of the aerodynamic been carried out: fuel consumption with
development (wind tunnel, CFD), operat- a flow meter, effective airflow with an
ing and flow-related mechanical condi- ultrasonic anemometer, height data with
tions must be met. Overall, these com- an inertial measurement system as well
prise: the sensitivity regarding the Reyn- as external wind data and temperature.
olds number of components and the It has so far proved possible to demon-
whole vehicle, typical turbulence spectra strate the c D value improvement, taking
of the road, boundary layers due to the the basic conditions into account. The
atmospheric wind, the rotation of the test process will undergo continuous
wheels and the relative movement of the improvement during series development.
road. After obtaining aerodynamic coef- The prototype tests within the scope of
ficients in these tests, further effects series development are planned for
which actually influence the aerody- November 2017.
namics will need to be considered, for
instance interfering flows caused by REFERENCES
overtaking, as well as wind-generated [1] European Federation for Transport and Environ-
wind-shadow effects caused by the traf- ment: Cleaner, safer trucks. Online: https://www.
transportenvironment.org/what-we-do/cleaner- safer-
fic ahead. trucks, access: 30 June 2017
A component designed under these [2] European Commission: Transport Whitepaper
conditions is then evaluated on test 2011. Online: https://ec.europa.eu/transport/
tracks/highways with the measurement themes/strategies/2011_white_paper_en, access:
30 June 2017
FIGURE 5 Detail of kinematics with the multi-joint of power and fuel savings, where the [3] Savvidis, D.: Heavy Duty Vehicles’ CO 2 Legisla-
system (© Betterflow, Edag) information on the disturbance variables tion in Europe and Vecto Simulation Tool. 8 th Forum
prevailing on the vehicle must provide to on Energy Efficiency in Transport: Energy Efficiency
make conclusions about the regression Regulation for Heavy-Duty (HD) Vehicles, Mexico
City (Mexico), 2015
techniques for the individual coefficients [4] Delgado, O.; Muncrief, R.: New Study on Tech-
TESTS IN REAL TRAFFIC of power demand. Such disturbance var- nology Potential for EU Tractor-Trailers. Road to Effi-
SITUATIONS iables comprise: the gradient and the ciency Workshop, The International Council on Clean
Transportation (ICCT), Brussels (Belgium), 2016
roadway conditions, the resulting air- [5] Directive 96/53/EC: Maximum authorized
The reason behind improving aerody- flow, temperature, air pressure, precipi- dimensions in national and international traffic.
namics is the real and effective reduction tation and wind data. Brussels (Belgium), May 2015
of CO 2 emissions and fuel consumption. After initial measurements on test [6] EP 2765064 A1: Flow guiding device for a
vehicle and vehicle, in particular an HGV, semi-
To this, it is important to initially define tracks, the Betterflow functional model trailer truck, HGV trailers or van. 13 August 2014

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