Ic Engine

INTERNAL COMBUSTION ENGINES

INTERNAL COMBUSTION ENGINES
Mihir Sen University of Notre Dame

November 11, 2009

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INTERNAL COMBUSTION ENGINES Outline

1 Outline 2 Basics 3 Classification 4 Terminology 5 Components 6 Operation 7 Thermodynamics 8 Parameters 9 Output

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INTERNAL COMBUSTION ENGINES Basics

Historical

Lenoir, 1860: first auto Otto and Langen, 1867: efficiency about 11% Diesel, by 1892: compression ignition engine

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INTERNAL COMBUSTION ENGINES Basics

Combustion engines
Chemical energy in fuel converted to thermal energy by combustion or oxidation Heat engine converts chemical energy into mechanical energy Thermal energy raises temperature and pressure of gases within engine, and gas expands against mechanical mechanisms of engine Combustion Internal: fuel is burned within the engine proper (including e.g. rocket engines, jet Engines, firearms) External: combustion is external to the engine (e.g. steam, Stirling engine, gas turbine)

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INTERNAL COMBUSTION ENGINES Classification

Classification of IC engines
Ignition Number of strokes Valve location Design Position and number of cylinders Air intake Fuel input method Fuel used Cooling Application

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INTERNAL COMBUSTION ENGINES Classification

Ignition

Spark ignition (SI): high-voltage electrical discharge between two electrodes ignites air-fuel mixture in combustion chamber surrounding spark plug Compression ignition (CI): air-fuel mixture self-ignites due to high temperature in combustion chamber caused by high compression, Diesel engine

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INTERNAL COMBUSTION ENGINES Classification

Number of strokes

Four-stroke: four piston movements over two engine revolutions for each engine cycle Two-stroke: two piston movements over one revolution for each engine cycle

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INTERNAL COMBUSTION ENGINES Classification

Valve location

Valves in head Valves in block One valve in head and one in block (less common)

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