How Squish Works:
1. Intake Stroke: Air is drawn into the combustion chamber through the intake valve.
2. Compression Stroke: The piston moves upwards, compressing the air.
3. Squish Zone: The combustion chamber is designed with a specific shape, usually with a bowl or recess in the piston crown. This creates a small gap between the piston and the cylinder head, known as the "squish zone."
4. Squish Action: As the piston approaches the top dead center (TDC), the compressed air in the main chamber is forced into the squish zone. This creates a rapid, turbulent flow of air.
5. Fuel Injection: Just before TDC, the fuel injector sprays the fuel into the squish zone. The turbulent air helps to mix the fuel and air thoroughly.
6. Combustion: The intense compression and the presence of hot air ignite the fuel, causing combustion and driving the piston down.
Benefits of Squish:
* Improved Fuel-Air Mixing: The turbulent flow in the squish zone ensures a more homogeneous mixture of fuel and air, leading to more complete combustion.
* Enhanced Combustion Efficiency: Better mixing results in faster and more efficient combustion, reducing emissions and improving fuel economy.
* Reduced Ignition Delay: The squish action helps to reduce the delay between fuel injection and ignition, leading to smoother engine operation.
* Lower NOx Emissions: By promoting more complete combustion, squish helps to reduce the formation of nitrogen oxides (NOx), a harmful pollutant.
In Summary:
Squish is a vital part of the diesel engine's combustion process. It's the result of the precise design of the combustion chamber and the piston, which forces the compressed air into a small space, creating turbulence that helps to mix fuel and air effectively. This leads to improved fuel economy, reduced emissions, and smoother engine operation.
