IE T he internal combustion engine (Ie) is a heat engine that converts chemical energy in a fuel into mechanical energy, usually made available on a rotating output shaft. Chemical energy of the fuel is first converted to thermal energy by means of combustion or oxidation with air inside the engine. This thermal energy raises the temperature and pressure of the gases within the engine, and the high- pressure gas then expands against the mechanical mechanisms of the engine. This expansion is converted by the mechanical linkages of the engine to a rotating crankshaft, which is the output of the engine. The crankshaft, in turn, is connected to a transmission and/or power train to transmit the rotating mechanical energy to the desired final use.
Internal combustion engines Engines for automotive and construction equipment may be classified in several ways. Fuel used light oil engine heavy oil engine Gas engine Bi-fuel engine Method of Fuel supply Through carburetor Multipoint port injection Single point throttle body Fuel injection at high pressure
Method of Ignition: Spark ignition Compression ignition Method of Cooling Water cooled engine Air cooled engine Speed Low speed engine Medium speed engine High speed engine Field of application Stationary engines for power generation Marine engines for propulsion of ships Automotive engines for land transport Aero engines for aircraft Locomotive engines for railways Lubrication system Wet sump engine Dry sump engine Pressure lubrication Method of control under variable load Quantity control engine Quality control engine Combined control engine
Intake: The cylinder is filled with a mixture of fuel and air in the correct proportions. Compression: The mixture in the cylinder is compressed by the piston. Power: The mixture is ignited and burned and the expanding gas drives the piston downward. Exhaust: The burned gases are expelled from the cylinder.
Intake stroke Compression stroke Power stroke Exhaust stroke
Indicated power Brake power Friction power Mechanical efficiency Brake mean effective pressure Thermal efficincy Fuel consumption Volumetric efficiency Criteria of performance
Torque measures an engine's ability to handle loads and accelerate, and is perhaps the best indicator of an engine's performance. Engines produce useful torque only over a limited range of rotational speeds
The ratio of an engine's combustion chamber volume at its largest to the volume at its smallest. It defines how much compression takes place within the chamber. A high compression ratio results in better fuel-air mixing and ignition, which leads to increased power and better overall engine efficiency. However, higher compression ratios make engines more susceptible to knocking with lower octane fuels, which can reduce efficiency or cause damage.
Wankel engine : Wankel engines are often lighter and simpler in design than equivalent piston engines. They are also typically more reliable (due to the reduction of moving parts) and have higher power-to-weight ratios. However, they suffer from less effective sealing which reduces their efficiency and lifespan. These engines are used mainly in racecars and sporting vehicles where reliability and lightness are considered more important than efficiency and engine life. operate using a rotor and shaft instead of a piston. The rotation of the shaft moves a three sided rotor which drives the movement of fuel through the system. In these engines, the different phases (intake, compression, power, and exhaust) take place in separate locations in the engine. The driveshaft rotates once for every time the engine fires in the Wankel design.