Internal Combustion Engine
Classifications of Engines
• The External combustion Engine.
• The Internal combustion Engine.
E.C.E (external combustion engine)
It is any engine that operates by
burning its fuel outside the engine.
engine is one in which the heat transfer to the working fluid occurs within the engine itself, usually by the combustion of fuel with the oxygen of air.
inner dead centre (IDC) outer dead centre(ODC),
air & fuel combustion
compresses
compression temperature & pressure very high
high temperature apply force move piston
exhaust
• It has no valves or camshaft mechanism.
• Less weight and easier to manufacture.
• High power to weight ratio.
• the 2-stroke engines have shorter life.
• They do not consume fuel efficiently.
• They produce lots of pollution.
• Sometimes part of the fuel leaks to the exhaust with the exhaust gases.
• Induction or Fuel Admission or Intake Stroke
• Compression Stroke
• Expansion or Power Stroke
• Exhaust Stroke
.
6-STROKE ENGINE
reduced by more than 40%
2-Stroke Working
4-Stroke Working
Strokes: Suction Stroke
Compression Stroke Ignition Stroke
Exhaust Stroke Air Suction Stroke
Air Exhaust Stroke
Valves: Suction Valve Air Inlet Valve Exhaust Valve Air Exhaust Valve
Valve 1 is open for gases inlet
Valve 2 is open for gases inlet in outer part of combustion chamber
Valve 3 is open for gases inlet from comustion chamber to gases chamber
Valve 4 is open for gases outlet in atmosphere
Valve 2 is open for gases outlet in hollow gaseous chamber
Valve 3 is open for gases inlet in combustion chamber
Basic DefinAtions
The process takes place from initiation to completion without an increase or decrease in the entropy of the system, i.e., the entropy of the system remains constant.
The process in which no heat leaves or enters the system ( either in expansion or compression ) is called Adiabatic Process.
The process in which the volume of the system remains constant even the pressure is increased or decreased is called Isochoric process.
The Ideal Otto cycle consists of four internally reversible processes in series.
Adiabatic Process and Isometric occurs.
1→2 isentropic compression or air as the piston moves from BDC to TDC
2→3 constant volume (isometric) heat addition to the fuel/air mixture from an external
source while the piston is at TDC (represents the ignition process and the subsequent
burning of fuel)
3→4 isentropic expansion (power stroke)
4→1 constant volume (isometric) heat rejection at BDC
Ideal otto cycle:
Practical otto cycle:
The Pratical Otto cycle consists of four internally reversible processes in series.
Adiabatic Process and Isometric doesn’t occurs
1→2 isentropic compression or air as the piston moves from BDC to TDC
2→3 constant volume (isometric) heat addition to the fuel/air mixture from an external
source while the piston is at TDC (represents the ignition process and the subsequent
burning of fuel)
3→4 isentropic expansion (power stroke)
4→1 constant volume (isometric) heat rejection at BDC
The Ideal Diesel cycle consists of four internally reversible processes in series.
Adiabatic Process and Isochoric occurs
1→2 adiabatic compression or air as the piston moves from BDC to TDC
2→3 constant pressure (isochoric)
3→4 adiabatic expansion (power stroke)
4→1 constant volume (isometric) exhaust of gases
Ideal diesel cycle:
Practical diesel cycle:
The Practical Diesel cycle consists of four internally reversible processes in series.
Adiabatic Process and Isochoric doesn’t occurs
1→2 air intake
2→3 compression
3→4 combustion with constant pressure
4→5 expansion
5→1 exhaust of gases
Difference betweenotto cycle and diesel cycle
Diesel Cycle
Questions ?
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