Analysis of Connecting Rod in a Four-Stroke Internal Combustion Engine

This report delves into the analysis of connecting rods within internal combustion engines, focusing on their critical role in converting reciprocating motion into rotational motion. The study begins with an abstract that highlights the importance of understanding connecting rod behavior and the application of MATLAB for simulating engine performance, particularly within an ideal Otto cycle framework. The report provides a historical overview of internal combustion engines, tracing their evolution from early gas engines to modern designs. It then classifies engine types based on stroke, fuel, and combustion methods, detailing the characteristics of two-stroke, four-stroke, steam, compression ignition, Stirling, reciprocating, and rotary engines. The report emphasizes the significance of internal combustion engines in various sectors, including transportation and agriculture, and their impact on technological advancements. The analysis of the connecting rod is crucial in understanding engine mechanics and the report underscores the importance of this component in modern engine design and operation. The report concludes by referencing relevant sources for further study.

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Abstract
In the transportation sector, an internal combustion engine is becoming the major mover for
energy transformation. The studying of connecting rod in engines is very important since it
enables us to understand how rotating motion is achieved in any engine and in this particular
study, the change of four-stroke IC engine was formulated as a function of crank angle by
assuming it is running as an ideal Otto Cycle. And MATLAB was used in performing further
analysis to determine the pressure of engine cylinder as well as the length of the axial of the
connecting rod. In this study, connective rod was chosen since it is one of the most important
part in engine because it is used in connecting the crankshaft in engines.

History of internal combustion engine
This type of engine mentioned above is a heat engine whereby combustion chamber allows the
combustion of fuel and oxidizer to take place. In this particular engine, high-pressure gases and
high temperature created by combustion expand and application of force to the turbines, nozzle,
rotor, and piston permits chemical energy to be transformed into valuable mechanical energy.
The invention and development of internal combustion engine is summarized as follows;
 1858-Joseph Jean born in Belgian came up with a double acting, electric- ignition
internal combustion engine fueled by coal gas.
 1862-A four-stroke engine was patented by a French civil engineer by the name
Allophone de Rochas.
 1873-Unsuccessful two-stroke engine though recognized as the first practical oil
engine was developed by an American engineer by the name George Brayton.
 1866-A more effective gas engine was developed by Nikolaus Otto and Eugen
Langen, engineers from German.
 1876-An invention of four-stroke engine known as Otto cycle was done by Nikolaus
Otto and later patented.
 1876-Dougald Clerk invented the first successful two-stroke engine.
 1883-A single-cylinder four-stroke engine that ran on stove gas was built by
Edouard Dalmare an engineer from German.
 1885- Modern gas engine prototype was invented by Gottlieb Daimler which led to
first four-wheeled motor vehicle.
 1886- The first patent for a gas-fueled car was received by Karl Benz.

 1889-A four-stroke engine with V-slant cylinder and valves with a shape of a
mushroom was built by Daimler.
 1890- A four stroke engine having four cylinder was built by Wilhelm Maybach.
Connecting rod
In a reciprocating engine, a piston is connected to a crankshaft using a connecting rod in order to
achieve a rotating motion. The connecting rod in modern combustion engine is made using steel
and this make it possible to rotate the crank.
Types of engines
The engines are grouped according to type of combustion, fuel used and type of stroke.
a) According to type of stroke
There are two stroke engines and they include 2-stroke and 4-stroke engine though the two-
stroke type of engine are outdated while the four-stroke engines are mostly used in automobiles.
The four-stroke engine simply means that four separated stroke is completed by the piston while
crankshaft is being rotated.
b) According to type of fuel used
The engines normally use different working fluid for example fuel, steam and even petrol. They
are explained below;
Steam engines
The engine mentioned above uses steam as its functioning fluid to carry out task mechanically
and they normally consist of three major units which include condenser, engine and the boiler.

Steam engine can be divided based on where the cylinder axis is positioned and according to
steam actions upon the piston.
Compression ignition engine
This type of engine was named after Rudolf Diesel in which elevation of air temperature in the
cylinder as a result of mechanical compression causes burning of fuel. The compression of air in
this type of engine upsurges the temperature inside the cylinder to a greater point that atomized
diesel fuel.
Stirling engine
The engine mentioned above is a heat energy that functions through expansion of air which is
working fluid. And this engine has an enduringly gaseous operating fluid. This type of engine
was developed by Robert Stirling in 1816 and this engine is able to reach 50% efficiency (Gupta,
2013, p. 53)
c) According to combustion
The type of engines grouped according to type of combustion include
Reciprocating engine
This kind of engine uses a single or numerous reciprocating pistons to allow pressure to be
converted into a spinning motion. This engine is suited to a numerous distributed generation
applications and are used throughout the industry and institution. There are two types of
reciprocating engine and they include diesel-cycle and Otto-cycle engine.

Rotary engine
A rotary engine is normally made using the cylinders’ odd number per row in a radial
arrangement in which during the operation, the crankshaft stayed motionless together with the
crankcase. This type of engine was mainly used in aviation but also it was being automobiles and
motorcycles in later years.
Importance of internal combustion engine
 The development of this particular engine made it possible for the mechanization of some
tillage and harvesting operations
 Internal combustion engine is continuing to maintain their position as the main mover for
energy transformation more so in the power and transport sector.
 An engine is assembly of moving parts converting one form of energy into another and in
automobiles, internal combustion engine converts chemical energy of the fuel into
motions in order to drive the car.
 Invention of internal combustion engine led to creation of industrial sector since many
industries started using the newly invented engine.
 The invention and development of the engine mentioned above has a reflective impact of
human life since it offers a comparatively lesser, insubstantial power source.
 Internal combustion engine improved agricultural sectors more so those that were doing
agriculture in large scale were using the engine to carry out irrigation.
 The innovation of this type of engine has exhibited a progress in practical machines for
example the generators thus making technological sector to grow.

References
Gupta, I. (2013). Fundamentals of internal combustion engines (2 ed., Vol. 2). OLMA Media Group.
Stone, R. (2012). Introduction to internal combustion engine (2 ed., Vols. 234-245). Adventure Works
Press.