What is the primary function of an internal combustion engine?

The primary function of an internal combustion engine is to convert heat energy into work by burning fuel. This process takes place when fuel is mixed with air and ignited within the engine's cylinders. The combustion generates high-temperature gases that expand rapidly, creating pressure which moves the engine's pistons. This movement is then transformed into mechanical energy, allowing the engine to perform work, such as turning the wheels of a vehicle.

The process fundamentally relies on the heat produced by combustion to perform mechanical tasks, which is a key characteristic of how internal combustion engines operate. Understanding this conversion process is crucial for grasping the principles of engine functionality and efficiency.