57
Superior
Technology
Exhaust gas
pressure
Boost
pressure
Functional description
Fundamental principle
A gas flows through a narrow pipe faster than
through a pipe without a constriction. The
prerequisite is that the same pressure is applied
in both pipes.
This physical principle is utilized by the
turbocharger with variable turbine geometry for
the purpose of achieving a constant boost
pressure in virtually all engine speed ranges.
Low engine speed
The volume and speed of the exhaust gas are
low. The cross section of the exhaust pipe is
constricted before the turbine wheel by the guide
vanes. The narrowed cross section forces the
exhaust gas to flow faster thus increasing the
speed of the turbine wheel.
The high rotary speed of the turbine guarantees
optimum boost pressure also at low engine
speed.
High engine speed
The exhaust volume and speed are high. The
guide vanes enable a larger cross section. The
maximum boost pressure is not exceeded.
Exhaust turbocharging
MSSP_001_053
MSSP_001_054
MSSP_001_055
Turbine wheel
Guide vane
Exhaust gas
pressure
Boost
pressure
Summary of Contents for SDI 55-5
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