How does a Spark Ignition Engine?
The spark ignition (SI) engine is an internal combustion engine that ignites a mixture of air and fuel through a spark. The spark ignition engine is also known as a petrol engine. The spark is generated made with the help of a plug. Since the spark is responsible for the combustion of fuel in this type of engine. This engine uses gasoline as fuel for its work. The principle of operation of the spark ignition engine is the otto cycle. The fuel from this engine is injected through the carburetor during the intake path. It has a light engine and is used in light vehicles such as motorcycles and cars.
Working of Spark Ignition Engine
The working of the Spark ignition engine is divided into four stages:
1) Suction stroke:
During this stroke, a mixture of air and fuel enters the cylinder.
First, the piston is lowered and a vacuum is created in the cylinder. The inlet valve system design allows the inlet valve to open while a vacuum is being created.
When a vacuum is created in the cylinder and the intake valve opens, a mixture of air and fuel enters the cylinder from the carburetor through the intake valve.
During this impact, the piston moves from the TDC (Top Dead Center) to the BDC (Low Dead Center).
The reason it is called an input shock is that during this impact the mixture is sucked into the cylinder and due to the load, that enters during this impact it is called a charged shock.
During this stroke, the intake valve opens and the exhaust valve remains closed.
2) Compression Stroke:
As the air-fuel mixture reaches the cylinder, the air-fuel mixture is compressed in the compression motion.
After the first stroke, the piston moves up and the air-fuel mixture is compressed.
Due to the density, the temperature and pressure of the air-fuel mixture increase.
When the piston reaches the Top Dead Center the compression stroke is complete. In this movement, the piston moves from the bottom dead center to the top dead center.
During this impact, both the inlet and outlet valves remain closed.
3) Power stroke:
In this stroke, the air-fuel mixture is ignited by a spark, and the air-fuel mixture burns and produces energy.
At the end of the compression stroke, the spark plug produces a spark. The spark ignited a mixture of air and fuel. The mixture begins to burn in the cylinder, the pressure, and temperature rise, and the burning air suddenly expands.
And the mixture of air and fuel burns in the cylinder. At this moment the mixture is in the highest position, when the mixture expands it creates an extraordinary thrust, pushes the piston down and the piston goes down at high speed. When the piston is lowered, the crankshaft makes a rotational movement.
During this stroke, the position moves from the high dead center (TDC) to the low dead center (BDC).
During this impact, both the inlet and outlet valves remain closed.
4) Exhaust stroke:
In this stroke of the spark ignition egnien, the exhaust gas or the burnt gas comes out of the cylinder.
The piston reaches the bottom dead center during the stroke. Subsequently, the piston moves from the BDC to the TDC. When the piston moves up, the exhaust valve opens at the same time and the exhaust gas or exhaust gas leaves the cylinder through the exhaust valve.
During this impact, the outlet valve opens and the inlet valve remains closed.
When the exhaust path is complete, all four movements are repeated and the engine continues to run.
Two strokes are required for the crankshaft to complete one rotation. In all four movements, the piston completed two revolutions of rotation.
Advantages of the SI engine
- low-cost
- Spark ignition engine produces less pollution than CI engine
- Compared to IC motors, these motors are smaller and therefore require less space.
- These motors are lightweight.
- Compared with the CI motor, the SI motor value is lower.
- These motors require lower maintenance costs.
Disadvantages of the SI Engine
- Under heavy load, these motors are cheaper.
- These engines have a high fuel consumption.
- Compared with the IC motor, its efficiency is lower.
- This device has a knocking problem.
Spark Ignition Engine Applications
- These cars are often used in two cycles such as motorcycles and scooters. The two-stroke SI engine is used on two wheels.
- SI radial engines are used in small aircraft.
- Si engines are also used in cars that use methane as fuel.
- These machines are also used inland transport aircraft.
- Four-stroke SI engines are used in vehicles, especially four-wheeled vehicles.
