F O C U S 1 5
age this, but it can make an excellent
contribution. Fuel consumption can
be reduced, for example, by raising
the compression ratio or by extracting
more power out of downsized engines,”
Paul Kapus explains.
THE DRIVABILITY OF A SERIES
PRODUCTION CAR
In May 2017, the AVL HyPer 200
with water injection was introduced
at the Vienna Motor Symposium.
Despite its small displacement,
the engine delivers top performance,
is RDE-compatible and drivable.
“Demonstrator vehicles show customers
that we are proficient in the
field of RDE-compatible concept vehicles
under series production boundary
conditions,” Matthias Neubauer
says, commenting on the drivability.
“Every customer can simply get into
the car, start the engine and drive
away. There are no complicated systems
you need to boot first; you can
drive the car like you would a seriesproduction
car. That’s what distinguishes
us from tuners who also build
powerful cars. Our concept vehicles
meet the requirements of volume production
and have very good drivability.
In other words, their transient
behavior and torque at low speeds are
very good.”
To develop the AVL HyPer 200 further
and make it RDE-compatible,
it was already designed to allow for
an increased catalyst volume, i.e. a
volume that is twice that of a series
engine. The larger catalyst volume
helps to convert emissions at high
mass flows, but also lowers the counter
pressure. Gas exchange is improved
– a positive pressure gradient
between inlet and outlet is reached,
even when traveling at high speeds.
This, in turn, improves knocking
behavior and, consequently, power
output and the tolerance of high
compression ratios. In a next step, a
particle filter is added to the exhaust
gas treatment system, which further
reduces the already very low levels of
particulate emissions. Consumption
and emission reduction was achieved
by injecting water – a method well
known in the field of aircraft engineering
and motor sports.
CUSTOMER-READY IN NO TIME
With the turbine entry temperature
being limited, conventional high-performance
engines require an additional
fuel injection for cooling and component
protection purposes. In the
case of the AVL HyPer 200, the necessary
cooling is achieved with water
instead of an added injection of gasoline.
Matthias Neubauer: “We inject
the gasoline straight into the combustion
chamber at a pressure of up to 350
bar. The additional water is supplied
by a low-pressure injection system at
7 bar, which means that the injection
is delivered into the intake port.” Water
has a much higher evaporation heat
than gasoline and has zero emissions.
If you replace gasoline with water to
reach a suitable turbine entry temperature,
you save gasoline. “And since
the gasoline quantity is calculated for
a lambda-1, i.e. for the stoichiometric
fuel-to-air ratio, the car is RDE compatible,”
Paul Kapus adds.
On the test track, the vehicle has already
driven up to 7,000 rpm full load
at lambda-1 operation, so the objective
of developing an RDE-compatible
engine has been met. “With the
simulation tools’ high level of precision,
AVL can cover the majority of
development tasks using simulation
and needs far fewer tests on the engine
testbed. That saves time and costs,”
Paul Kapus explains. The high-performance
engine with water injection
was first presented to customers
in April 2017. It is now time to
start tackling the next projects. The
fact that Kapus and Neubauer thoroughly
enjoy innovation is clearly visible:
“There are so many measures to
improve fuel efficiency that are currently
gaining momentum. We will,
of course, be testing a good number
of other technologies in demonstrator
vehicles in the future.” <
>
The water is not injected straight into the cylinder but into the intake manifold upstream of the inlet
valve at a relatively low pressure (7 bar).