BMW 135 CABRIOLET BROCHURE 2010 Wartungshandbuch PDF herunterladen (Seite 11)

20 21

THE WINDS

OF CHANGE.

The Air Curtain, which reduces air resistance at the

wheel arches of the     BMW    i, was developed

in the turbulent roar of a new high-tech wind tunnel.

In the giant wind tunnel at the BMW Group’s

Aerodynamic Test Center in Munich, driving

reality is turned inside out: it’s the vehicle

that stays still while its environment moves

around it. A huge rotor that consumes ﬂ .ﬂ

mega watts of power drives ﬁ  ,   cubic

yards of air around an air ow ring. Before

reaching the test track, the air is forced

through a duct to accelerate its speed six

times. Road conditions are simulated using

𶉁 ve thin steel rolling tracks. The wheels of

the test vehicle – in this case, the BMW

𶅉 ﬁ 𶅖 i Convertible – are driven by four narrow

belts, while the long central belt under the

car moves at exactly the same speed. This

complex arrangement ensures that the air ow

at the car’s under carriage, wheels and wheel

arches is almost identical to that of a real

driving situation. It’s as if the very road itself

were being put to the test.

When it comes to aerodynamics, a 𶅉  per cent

reduction in air resistance leads to a good

ﬁ . percent reduction in fuel consumption.

Although the new 𶅉 ﬁ 𶅖 i Convertible body is

already aerodynamically optimized, this is

actually responsible for only ﬂ  percent of

the vehicle’s total air resistance. Ten percent

is caused by the cooling air for the engine,

transmission and brakes; ﬁ  percent from the

vehicle underbody; and the 𶉁 nal 𶅑  percent is

produced at the wheels and the wheel arches.

In all these areas, the new 𶅉 Series Convertible

still had room for improvement.

This Aerodynamic Test Center testing has

yielded an innovative solution: the new Air

Curtain in the front air dam, which makes

its debut in the 𶅉 ﬁ 𶅖 i. This dynamic feature

protects the front wheels from headwind

and signi𶉁 cantly reduces turbulence over

the front tires. Air is taken in through vents

in the front air dam. As the vent ducts narrow,

the air picks up speed. It exits at high speed

through narrow slits, covering the outer face

of the front wheels like a curtain. This Air

Curtain acts like an invisible wheel cover:

imperceptible yet highly effective.

Used in conjunction with the optimized

cooling air ducts and a smoothed-off under-

carriage, the new Air Curtain provides the 𶅉 ﬁ 𶅖 i

with an excellent air-resistance coef𶉁 cient, as

well as reduced uplift. The result: improved

fuel ef𶉁 ciency – and increased vehicle stability.

Right: The air ow over the new BMW 𶅉 Series Convertible

is made visible by means of a smoke tracer. The slighter the

turbulence created, the lower the air resistance.

Left: Aerodynamics experiments in the giant testing bay

are controlled from the wind tunnel’s control room.

To the rear of the test track, tall hemispherical partitions

guide the air ow back in the opposite direction.

Information Provided by:

1 2 ... 6 7 8 9 10 11 12 13 14 15 16 ... 33 34

Kommentare zu diesen Handbüchern

Keine Kommentare

BMW 135 CABRIOLET BROCHURE 2010 Wartungshandbuch Seite 11

Kommentare zu diesen Handbüchern

Verwandte Produkte und Handbücher für Autos BMW 135 CABRIOLET BROCHURE 2010