Internal combustion engine

Definition

An internal combustion engine (ICE) is a heat engine where the combustion of fuel occurs with an oxidizer in a combustion chamber. The expansion of the high-temperature and high-pressure gases produced by combustion applies direct force to components, such as pistons or turbine blades.

5 Must Know Facts For Your Next Test

1. Internal combustion engines operate on the principles outlined by the Second Law of Thermodynamics.
2. The efficiency of an ICE is limited by the Carnot efficiency, which depends on the temperature difference between the heat source and sink.
3. Common types of ICEs include four-stroke and two-stroke engines.
4. Heat generated in an ICE must be managed to avoid overheating, typically using cooling systems like radiators.
5. The Otto cycle describes the thermodynamic processes in a typical gasoline-powered internal combustion engine.

Review Questions

• What thermodynamic principle limits the efficiency of an internal combustion engine?
• Explain how the Carnot efficiency impacts an internal combustion engine's performance.
• Describe the main differences between a four-stroke and a two-stroke internal combustion engine.

Related terms

Otto Cycle: A thermodynamic cycle that describes the functioning of a typical spark-ignition piston engine, often found in automobiles.

Carnot Efficiency: The theoretical maximum efficiency that can be achieved by any heat engine, defined by the temperature difference between its hot and cold reservoirs.

Second Law of Thermodynamics: : A fundamental principle stating that total entropy can never decrease over time for an isolated system; it also implies that energy transformations are not completely efficient.