What is an internal combustion engine?
An internal combustion engine (ICE or IC engine) is a heat engine in which fuel combustion occurs using an oxidizer (usually air) in a combustion chamber that is an integral part of the working fluid flow circuit. In internal combustion engines, the expansion of hot and high-pressure gases produced by combustion imposes direct forces on some engine components.
Such engines derive their energy from the heat released during the combustion of the unreacted working fluid, a mixture of oxidant and fuel. This process takes place inside the engine and is part of the thermodynamic cycle of the device.
The useful work produced by an internal combustion (IC) engine comes from the hot gaseous products of combustion acting on the engine’s moving surfaces such as pistons, turbine blades, or nozzles.
The internal combustion engine is the most widely applied and widely used power generation device at present. For example, we can mention gasoline engines, diesel engines, gas turbine engines and rocket propulsion systems.
Internal combustion engines are divided into two groups, continuous combustion engines and intermittent combustion engines. Continuous combustion engines are characterized by a constant flow of fuel and oxidant to the engine.
Maintains a stable flame in an engine (such as a jet engine). Intermittent combustion engines are characterized by the periodic combustion of air and fuel and are commonly known as reciprocating engines. Separate volumes of air and fuel are processed cyclically. Gasoline piston engines and diesel engines are examples of this second group.
The most common internal combustion engines are four-stroke engines, gasoline engines, homogeneous charge, spark ignition engines. This is due to its excellent performance as a driving force in the ground transportation industry.
Read More: What is External Combustion Engine?
How does an internal combustion engine work?
The engine then partially converts the energy from combustion into work. The engine consists of a fixed cylinder and a moving piston. The expanding combustion gases push the piston, which in turn rotates the crankshaft. Ultimately, through a system of gears in the powertrain, this motion drives the vehicle’s wheels.
Combustion, also called as burning, is a basic chemical process that releases energy from a mixture of fuel and air. In the internal combustion engine (ICE), ignition and combustion of fuel takes place in the engine itself.
The two main types of internal combustion engines are spark ignition (SI) engines in which the fuel is ignited by a spark. In compression ignition (CI) engines, the increase in temperature and pressure during compression is sufficient to ignite the fuel spontaneously.
Spark-ignition engines are called gasoline, petrol, or gas engines because of their common fuel, and they are called Otto engines after their inventors. Compression engines are also known as diesel or oil engines. The name of this fuel is taken from the name of its inventor.
During each revolution of the crankshaft, the piston has two strokes, and both types of engines can be designed to operate with four or two piston strokes. The four-stroke operation cycle is as follows.
- Intake strokes. The intake stroke opens the intake valve and the piston moves to the bottom of the cylinder and sucks in air. For spark-ignition engines, fuel is usually mixed with air.
- The compression strokes. The compression stroke closes both valves and the piston moves to the top of the cylinder. Ignition occurs when the piston approaches top dead center (TDC). For compression ignition engines, fuel is injected toward the end of the compression stroke.
- The combustion and power stroke. Combustion spreads through the charge, increasing pressure and temperature and pushing the piston down. At the end of the power stroke, the exhaust valves are opened and the irreversible expansion of the exhaust gases is called “blowdown”.
- On the exhaust stroke, the exhaust valve remains open and the remaining gas is expelled by the movement of the piston to the top of the cylinder. When the exhaust valve closes at the end of the exhaust stroke, exhaust gases remain. These will dilute the next charge.
A four-stroke cycle is sometimes summarized as ‘suck, squeeze, bang, and blow’ This cycle is only completed once every two revolutions, so the valve gear (and fuel injectors) must be driven by a mechanism that operates at half an engine revolution. Part of the force from the expansion stroke is stored in the flywheel to power the other three strokes.
Applications of internal combustion engines
Internal combustion engines are the most broadly applied and widely used power-generating devices currently in existence. Examples include gasoline engines, diesel engines, gas-turbine engines, and rocket-propulsion systems.
IC engine has many applications like,
- Gasoline Engines: Automotive, Marine, Aircraft
- Gas Engines: Industrial Power
- Diesel Engines: Automotive, Railways, Power, Marine
- Gas Turbines: Power, Aircraft, Industrial, Marine
An internal combustion engine (ICE or IC engine) is a heat engine in which the combustion of a fuel occurs with an oxidizer (usually air) in a combustion chamber that is an integral part of the working fluid flow circuit.
In 1823, Samuel Brown patented the first internal combustion engine to be applied industrially in the U.S.; one of his engines pumped water on the Croydon Canal from 1830 to 1836.
The first commercially successful internal combustion engine was created by Étienne Lenoir around 1860 and the first modern internal combustion engine was created in 1876 by Nicolaus Otto. In 1872, American George Brayton invented the first commercial liquid-fueled internal combustion engine.
The engine consists of a fixed cylinder and a moving piston. The expanding combustion gases push the piston, which in turn rotates the crankshaft. Ultimately, through a system of gears in the powertrain, this motion drives the vehicle’s wheels.
The first commercially successful internal combustion engine was created by Étienne Lenoir around 1860 and the first modern internal combustion engine was created in 1876 by Nicolaus Otto (Otto engine).
Internal combustion engines (ICE) are the most common form of heat engines, as they are used in vehicles, boats, ships, airplanes, and trains. They are named as such because the fuel is ignited in order to do work inside the engine. The same fuel and air mixture is then emitted as exhaust.