- During the intake stroke, a piston moves down within the cylinder, creating a low pressure area that draws air into the cylinder through an intake valve.
- As the piston reaches the bottom of the cylinder, the intake valve closes, and the piston begins to move up, compressing the air within the cylinder. This increases its pressure and temperature.
- Near the top of the compression stroke, fuel is injected into the highly compressed air, either directly into the cylinder or through a fuel injector.
- The fuel and air mixture is then ignited by a spark plug, causing it to rapidly combust and expand, driving the piston down in the power stroke.
- At the bottom of the power stroke, an exhaust valve opens, allowing the high-pressure exhaust gases to be expelled from the cylinder and out of the engine.
- The piston moves back up to the top of the cylinder, completing the cycle and preparing the engine for the next intake stroke.
The exhaust gases from an open cycle engine are typically released into the atmosphere through an exhaust system, and they can contain pollutants such as carbon monoxide, hydrocarbons, and nitrogen oxides. To reduce these emissions, many modern internal combustion engines incorporate various emission control systems, such as catalytic converters and exhaust gas recirculation (EGR) systems.
Compared to closed-cycle engines, open cycle engines are generally simpler in design and have better fuel efficiency. However, they also tend to produce higher emissions.
