Describe the various process that takes place in 4-stroke diesel engine

Here are the processes that take place in a 4-stroke diesel engine:

1. Intake (Suction) Stroke: The piston moves downwards, creating a vacuum. The intake valve opens, and only air is drawn into the cylinder. The exhaust valve remains closed.

2. Compression Stroke: Both intake and exhaust valves close. The piston moves upwards, compressing the air in the cylinder. This compression significantly increases the air's temperature and pressure.

3. Power (Combustion/Expansion) Stroke: As the piston reaches the top of the compression stroke, fuel is injected into the hot, compressed air. The high temperature ignites the fuel, causing a rapid expansion of gases that pushes the piston downwards, generating power. Both valves remain closed.

4. Exhaust Stroke: The exhaust valve opens, and the piston moves upwards, pushing the burnt gases out of the cylinder through the exhaust manifold. The intake valve remains closed.