If the burning takes place inside the cylinder, it is an internal combustion engine.
Internal Combustion Heat Engine
The fuel can be wood, coal, gas, or oil. The heat energy from nuclear reactions has also been used to run heat engines. Nuclear-powered submarines and aircraft carriers are in use today. Some of the earliest heat engines were external combustion steam engines.
The following are the four stroke of internal combustion petrol engine.
The four-stroke-cycle of a petrol engine
Four strokes are as follows:
Each upward or downward movement of the piston is called a stroke. During the first stroke (Intake) the piston moves down to draw a mixture of air and petrol into the cylinder. During the second stroke (Compression), it moves upwards to compress it. During the third stroke (Expansion or Power), the piston is pushed forcefully downwards when a spark from the plug ignites the mixture. During the fourth stroke (Exhaust), the piston moves upwards to push the burnt gases out of the cylinder.
The two valves are opened and closed at appropriate times to let in the fresh mixture, seal the cylinder or allow the burnt gas out. When the engine is running fast, the whole process is repeated about fifty times per second.
The crankshaft of the engine is pushed round only during the power stroke. A heavy wheel attached to the crankshaft keeps the engine turning through the other three strokes, this is needed to rid the engine of burnt gases and to prepare a fresh mixture for ignition. The engine does useful work with some of the energy supplied to it. The rest of the energy is wasted as heat.
A sparking plug has a metal threaded shell, electrically isolated from a central electrode by a porcelain insulator. The central electrode, which may contain a resistor, is connected by a heavily insulated wire to the output terminal of an ignition coil or magneto.
The useful work done by an engine is called the work output. The input energy. output work and efficiency of a few engines are shown below.
Energyinput
Engine
Workoutput
Efficiency
100J
Petrol
25J
25%
100J
Diesel
35J
35%
Efficiency of petrol and diesel engines compared
" />External Combustion Heat Engine
If the burning takes place inside the cylinder, it is an internal combustion engine.
Internal Combustion Heat Engine
The fuel can be wood, coal, gas, or oil. The heat energy from nuclear reactions has also been used to run heat engines. Nuclear-powered submarines and aircraft carriers are in use today. Some of the earliest heat engines were external combustion steam engines.
The following are the four stroke of internal combustion petrol engine.
The four-stroke-cycle of a petrol engine
Four strokes are as follows:
Each upward or downward movement of the piston is called a stroke. During the first stroke (Intake) the piston moves down to draw a mixture of air and petrol into the cylinder. During the second stroke (Compression), it moves upwards to compress it. During the third stroke (Expansion or Power), the piston is pushed forcefully downwards when a spark from the plug ignites the mixture. During the fourth stroke (Exhaust), the piston moves upwards to push the burnt gases out of the cylinder.
The two valves are opened and closed at appropriate times to let in the fresh mixture, seal the cylinder or allow the burnt gas out. When the engine is running fast, the whole process is repeated about fifty times per second.
The crankshaft of the engine is pushed round only during the power stroke. A heavy wheel attached to the crankshaft keeps the engine turning through the other three strokes, this is needed to rid the engine of burnt gases and to prepare a fresh mixture for ignition. The engine does useful work with some of the energy supplied to it. The rest of the energy is wasted as heat.
A sparking plug has a metal threaded shell, electrically isolated from a central electrode by a porcelain insulator. The central electrode, which may contain a resistor, is connected by a heavily insulated wire to the output terminal of an ignition coil or magneto.
The useful work done by an engine is called the work output. The input energy. output work and efficiency of a few engines are shown below.
Energyinput
Engine
Workoutput
Efficiency
100J
Petrol
25J
25%
100J
Diesel
35J
35%
Efficiency of petrol and diesel engines compared
">External Combustion Heat Engine
If the burning takes place inside the cylinder, it is an internal combustion engine.
Internal Combustion Heat Engine
The fuel can be wood, coal, gas, or oil. The heat energy from nuclear reactions has also been used to run heat engines. Nuclear-powered submarines and aircraft carriers are in use today. Some of the earliest heat engines were external combustion steam engines.
The following are the four stroke of internal combustion petrol engine.
The four-stroke-cycle of a petrol engine
Four strokes are as follows:
Each upward or downward movement of the piston is called a stroke. During the first stroke (Intake) the piston moves down to draw a mixture of air and petrol into the cylinder. During the second stroke (Compression), it moves upwards to compress it. During the third stroke (Expansion or Power), the piston is pushed forcefully downwards when a spark from the plug ignites the mixture. During the fourth stroke (Exhaust), the piston moves upwards to push the burnt gases out of the cylinder.
The two valves are opened and closed at appropriate times to let in the fresh mixture, seal the cylinder or allow the burnt gas out. When the engine is running fast, the whole process is repeated about fifty times per second.
The crankshaft of the engine is pushed round only during the power stroke. A heavy wheel attached to the crankshaft keeps the engine turning through the other three strokes, this is needed to rid the engine of burnt gases and to prepare a fresh mixture for ignition. The engine does useful work with some of the energy supplied to it. The rest of the energy is wasted as heat.
A sparking plug has a metal threaded shell, electrically isolated from a central electrode by a porcelain insulator. The central electrode, which may contain a resistor, is connected by a heavily insulated wire to the output terminal of an ignition coil or magneto.
The useful work done by an engine is called the work output. The input energy. output work and efficiency of a few engines are shown below.
Identify the different parts of an internal combustion engine.
Describe the operation of the sparking plug.
Describe the different strokes in a four stroke internal combustion engine
Describe efficiency of a diesel and petrol engine
CONTENT
A heat engine is a device that uses heat energyEnergy is the property of matter and radiation which is mani... More to do workWork is The transfer of energy from one physical system to a... More. The engine does workWork is The transfer of energy from one physical system to a... More by changing heat energyEnergy is the property of matter and radiation which is mani... More into energyEnergy is the property of matter and radiation which is mani... More of motionMotion is the act of changing location from one place to ano... More.
If the burning takes place outside the cylinder, the engine is an external combustion engine.
External Combustion Heat Engine
If the burning takes place inside the cylinder, it is an internal combustion engine.
Internal Combustion Heat Engine
The fuel can be wood, coal, gas, or oil. The heat energyEnergy is the property of matter and radiation which is mani... More from nuclear reactions has also been used to run heat engines. Nuclear-powered submarines and aircraft carriers are in use today. Some of the earliest heat engines were external combustion steam engines.
The following are the four stroke of internal combustion petrol engine.
The four-stroke-cycle of a petrol engine
Four strokes are as follows:
Each upward or downward movement of the piston is called a stroke. During the first stroke (Intake) the piston moves down to draw a mixture of air and petrol into the cylinder. During the second stroke (CompressionCompression: The process or result of becoming smaller or pr... More), it moves upwards to compress it. During the third stroke (Expansion or PowerPower in physics is the rate of doing work; measured in watt... More), the piston is pushed forcefully downwards when a spark from the plug ignites the mixture. During the fourth stroke (Exhaust), the piston moves upwards to pushAction force is The force exerted by one body on a second bo... More the burnt gases out of the cylinder.
The two valves are opened and closed at appropriate times to let in the fresh mixture, seal the cylinder or allow the burnt gas out. When the engine is running fast, the whole process is repeated about fifty times per second.
The crankshaft of the engine is pushed round only during the powerPower in physics is the rate of doing work; measured in watt... More stroke. A heavy wheel attached to the crankshaft keeps the engine turning through the other three strokes, this is needed to rid the engine of burnt gases and to prepare a fresh mixture for ignition. The engine does useful workWork is The transfer of energy from one physical system to a... More with some of the energyEnergy is the property of matter and radiation which is mani... More supplied to it. The rest of the energyEnergy is the property of matter and radiation which is mani... More is wasted as heat.
A sparking plug has a metal threaded shell, electrically isolated from a central electrode by a porcelain insulator. The central electrode, which may contain a resistor, is connected by a heavily insulated wire to the output terminal of an ignition coil or magneto.
The useful workWork is The transfer of energy from one physical system to a... More done by an engine is called the workWork is The transfer of energy from one physical system to a... More output. The input energyEnergy is the property of matter and radiation which is mani... More. output workWork is The transfer of energy from one physical system to a... More and efficiency of a few engines are shown below.
EnergyEnergy is the property of matter and radiation which is mani... Moreinput
Engine
WorkWork is The transfer of energy from one physical system to a... Moreoutput
Identify the different parts of an internal combustion engine.
Describe the operation of the spark plug.
Describe the different strokes in a four stroke internal combustion engine
Describe efficiency of a diesel and petrol engine
Course Content
Types of Heat Engines
o. A heat engine is a device that uses heat energy to do work.
oThe heat needed to increase the pressure inside the cylinder is released in the burning, or combustion, of a fuel.
oIf the burning takes place outside the cylinder, the engine is an external combustion engine.
oIf the burning takes place inside the cylinder, it is an internal combustion engine.
oInternal combustion engine is a device converting the energy of a fuel-air mixture burning within a combustion chamber into mechanical energy.
Types of Heat Engines
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Functions of Four-stroke Engines
Most petrol engine operates on a series of four strokes, or movements of piston
The engine consists of four cylinders in different phases of the engine cycle (intake, compression, expansion and exhaust). Each cylinder has an inlet and exhaust valves, opening and closing of which is controlled by the cam mechanism. Each piston is joined to the crank pin of the crankshaft through the connecting rod.
The efficiency, E, of any heat engine can be with the formula,
E=W/Q_H
