1.
INTERNAL COMBUSTION
ENGINES & GAS TURBINES
PRESENTATION BY
SUBHOJIT DAS
BRANCH – MECHANICAL ENGINEERING
UNIVERSITY ROLLNO - 12000721061
YEAR – 3RD
SEMESTER – 6TH
SUBJECT CODE -PE- ME601A
SECTION- ME2X

2.
INTRODUCTION
The two-stroke engine only requires two-piston
movements (one complete cycle) to generate
power. The cycle is completed in two-stroke i.e.,
one revolution of the crankshaft. Only two-piston
stroke is required to complete the process, one for
compressing the fresh air and the other for
expansion or power stroke.

3.
CI ENGINES
Compression-Ignition Engine is also called as
Diesel Engine which is name after Rudolf Diesel, is
an internal combustion engine. CI Engine works by
compressing only the air, thus increase the
temperature inside the cylinder to such a high
degree that atomized diesel fuel injected into the
combustion chamber Ignites by the fuel injector
spontaneously.

4.
CONSTRUCTION OF 2-STROKE CI
ENGINE :
The two-stroke CI engine consists of a cylinder whose one end
is fitted with a cover for the placement of fuel injector and the
other is fitted with the crankcase. There are three ports in the
cylinder i.e., an inlet port, exhaust port, and transfer port. The
opening and closing of these ports depend on the piston
movement.
A flywheel is a mechanical device that is used to store energy
and atomized fuel is injected by a fuel injector to the
combustion chamber which ignites the air. In a two-stroke
engine, we get Power from expansion stroke. The size of a
flywheel in four-stroke is bigger than a two-stroke.

5.
PROCESS OF 2-STROKE CI ENGINE:
1) Suction + compression :-
When the piston moves from BDC to TDC the inlet port opens and the
fresh air enters easily due to less pressure inside the crankcase(cylinder).
During this, the transfer port remains closed. But as soon as the piston
reaches TDC, the air already present in TDC compressed and fuel is being
injected which ignites the compressed fuel. Now power stroke begins.
2)Power Stroke (Expansion + Exhaust) :-
Now, due to high pressure in TDC, the piston moves from TDC to BDC. The
Inlet port will be closed and the exhaust port will be open. Transfer port
also opens. Now, the fresh air moves upwards through the transfer port and
the exhaust gases move outward. When the piston moves TDC to BDC
pressure inside the crankcase increases, due to which fresh air comes above
the piston through the transfer port and pushes the exhaust gases due to
which exhaust gases exit through the exhaust port. The process is known as scavenging.

6.
LOSSES IN TWO STROKE ENGINE
1)During the scavenging process part of the fresh air also comes out through the
exhaust port.
2)When the fresh air comes above the piston through the transfer port then part
of the lubricant also flows with it, due to which:-
•Friction loss increases.
•Compression efficiency of fuel decreases.

7.
DIFFERENCE BETWEEN TWO STROKE
SI AND CI ENGINE

8.
REFRENCES:-
• Dabelstein, Werner; Reglitzky, Arno; Schütze, Andrea; Reders, Klaus; Brunner,
Andreas (2016). "Automotive Fuels". Ullmann's Encyclopedia of Industrial
Chemistry. Weinheim: Wiley-VCH. pp. 1–
41. doi:10.1002/14356007.a16_719.pub3.
• ^ Naijar, Yousef S.H. (2009). "Alternative Fuels for Spark Ignition Engines". The
Open Fuels & Energy Science Journal. 2 (2): 1–
9. doi:10.2174/1876973X01002010001.
• https://mechomotive.com/two-stroke-ci-engine/

9.
THANK YOU