EN
L 290/282
Official Journal of the European Union
Symbol
Units
CD(Y)
4.3.2.5.1.
10.11.2022
Description
aerodynamic angle Y
drag
coefficient
at
yaw
D
N
drag
Daero
N
aerodynamic drag
Df
N
front axle drag (including driveline)
Dgrav
N
gravitational drag
Dmech
N
mechanical drag
Dr
N
rear axle drag (including driveline)
Dtyre
N
tyre rolling resistance
(dh/ds)
-
sine of the slope of the track in the direction of travel (+ indicates ascending)
(dv/dt)
m/s2
acceleration
g
m/s2
gravitational constant
mav
kg
arithmetic average mass of the test vehicle before and after road load determination
me
kg
effective vehicle mass including rotating components
ρ
kg/m3
t
s
time
T
K
temperature
v
km/h
vehicle speed
vr
km/h
relative wind speed
Y
degrees
air density
yaw angle of apparent wind relative to direction of vehicle travel
General form The general form of the equation of motion is as follows:
Äme
Í Î dv ¼ Dmech þ Daero þ Dgrav dt
where: Dmech = Dtyre + Df + Dr; Daero =
Ä 1Ö 2
ρCd ðYÞAf v2d ;
Dgrav = m Ü g Ü
Ê Ì dh ds
In the case that the slope of the test track is equal to or less than 0.1 per cent over its length, Dgrav may be set to zero.