The document discusses diesel engines. It outlines that a diesel engine converts chemical energy from fuel into mechanical energy. It operates by compressing air which ignites fuel, causing the piston to move. There are two main types: two-stroke engines which complete a cycle in two strokes, and four-stroke engines which complete a cycle in four separate strokes - intake, compression, power, and exhaust. Diesel engines are widely used to power vehicles, generators, and machinery due to their efficiency.

1. Diesel Engine
By: Muhammad Yousuf Chhajro

2. Outlines
 Diesel engine
 Two stroke
 Four stroke
 Differences
 Applications

4. Engine is a motor which converts
chemical energy into mechanical energy
 The diesel engine also known as
a compression-ignition engine that uses
the heat of compression of air to
initiate ignition and burn the fuel
 The air required for the diesel engine is
drown through the air filter from the
atmosphere and compressed inside the
cylinder.
 The fuel from the diesel engine is drawn
through a filter and injected into the
cylinder through fuel injectors.
 Because of the high temperature and
pressure of the compressed air, the fuel
burns and the burnt gases expand to do
work on the moving part inside the
cylinder called piston.

5.  This movement of the piston rotates a
flywheel and the engine is directly coupled to
electric generator
 The gases after expansion inside the cylinder
is exhausted into the atmosphere and passes
through a silencer in order to reduce the
noise.
 Incoming air is compressed until its
temperature reaches about 1,000°F (540°C).

6. Diesel engines are
manufactured in two
stoke and four stroke versions

7. Two stroke
 A two-stroke, or two-
cycle, engine is a type
of internal combustion
engine
 which completes a power
cycle in only one crankshaft
revolution and with two
strokes, or up and down
movements, of the piston

8. Intake: Air is drawn into the crank case(a
case or covering enclosing a crankshaft) by
vacuum and then into the cylinder.
Compression: Air is then compresses inside
the cylinder.
Power: Fuel is injected trough fuel injector
air is ignited forcing the piston down
exposing the exhaust port.
Exhaust: The exhaust gases are forced out
by the incoming fuel air mix

9. Four stroke
 A four-stroke engine (also
known as four-cycle) is
an internal combustion
engine in which
the piston completes four
separate strokes
 A stroke refers to the full
travel of the piston along
the cylinder

10.  Intake Stroke
• Piston moves from TDC(top dead center)
to BDC(bottom dead center) creating
vacuum in the cylinder
• Intake valve opens allowing only air to
enter the cylinder and exhaust valve
remains closed
 Compression Stroke
• Both valves stay closed
Piston moves from BDC to TDC, the air is
compressed
• Compressing the air to this extent
increases the temperature inside the
cylinder to above 1000 degree F

11.  Power Stroke
• Both valves stay closed
• When the piston is at the end of
compression stroke(TDC) the injector
• sprays a mist of diesel fuel into the
cylinder.
• When hot air mixes with diesel fuel an
explosion takes place in the cylinder
• Expanding gases push the piston from
TDC to BDC
 Exhaust Stroke
• Piston moves from BDC to TDC
• Exhaust valve opens and the exhaust
gases escape
• Intake valve remains closed

13. Uses of Diesel Engine