Internal Combustion Engine-Bhavin

8/8/2019 Internal Combustion Engine-Bhavin

1/17

Internal Combustion

Engines

*Introduction

*Fuels

*Four Stroke Engine

*Parts of a four stroke engine


2/17

Introduction


3/17

Classification of IC engine

Engines can be classified in manydifferent ways: By the engine cycle used,

the layout of the engine, source ofenergy, the use of the engine, or by thecooling system employed.


4/17

Fuels

Why are nearly all vehicles and enginespowered by gasoline?

extremely high energy density

cheap (relative to other sources)

easy and safe to move around


5/17

Fuels

Why not use other fuels?

Size of engines needed to utilize thesefuels is impractical for automobileslawnmowers etc.

Convenience

it takes 15 seconds to pump a gallon of gasvs. several hours to recharge batteries (i.e.electric cars)


6/17

Fuels

What are other types of fuels that can beused?

Wood- steam engines

Coal- steam engines

Oil

Electricity


7/17

Internal Combustion

Where do we get internal combustion?

The idea here is to take a fuel (gasoline for

example) and burn it in an engine to createmovement of cars and other gas poweredmachines. This is where we get internalcombustion engines.


8/17

Internal Combustion

A cannon uses the basicprinciples of internalcombustion engines. Ifyou take a small amountof high energy fuel (likegasoline) in a small,enclosed space and ignite

it, an incredible amountof energy is released inthe form of expanding

gas.


9/17

The four-stroke cycle

Almost all engines use a four-strokecombustion cycle to convert gasoline into

motion. This is also known as the Otto cycle in honor

of Nikolaus Otto who invented it in 1867.

This process takes the basic example of acannon several steps further.


10/17


The four strokecombustion cycle

consists of: 1. Intake

2. Compression

3. Combustion

4. Exhaust


11/17


The piston starts atthe top, the intake

valve opens and thepiston moves down tolet the engine take ina full cylinder of air

and gasoline duringthe intake stroke

The piston thenmoves up to

compress theair/gasoline mixture.This makes theexplosion more

powerful.


12/17


When the pistonreaches the top, the

spark plug emits aspark to ignite thegasoline/air mixture.

The gasoline/air

mixture explodesdriving the pistondown.

The the pistonreaches the bottom of

its stroke the exhaustvalve opens and theexhaust leaves out ofthe tailpipe.

The engine is readyfor another cycle.


13/17

Parts of an engine

Cylinder- where the piston moves up anddown. Most lawnmowers are 1 cylinder

while automobiles are 4,6,8, and 10. Spark plug- supplies spark for the fuel/air

mixture.

Valves- let air in and exhaust out.Note: both valves are closed during thecompression stroke.


14/17

Parts of an engine

iston- cylindrical piece of metal that moves upand down the cylinder.

Piston rings- rings provide a sliding sealbetween the piston and cylinder.

Rings serve two purposes:

prevent fuel/air from leaking into the sump

prevent oil from entering the combustionchamber


15/17

Parts of an engine

Combustion chamber- area where combustionand compression takes place.

Connecting rod- connects the piston to thecrankshaft.

Crankshaft- the crankshaft turns the up anddown motion of the piston into circular motion

Sump- (oil pan) contains and collects oil forlubrication


16/17

Parts of an engine


17/17

Applications of IC engine

Internal combustion engines are mostcommonly used for mobile propulsion in vehiclesand portable machinery

In mobile equipment, internal combustion is

advantageous since it can provide high power-to-weight ratios together with excellent fuelenergy density

Where very high power-to-weight ratios are

required, internal combustion engines appear inthe form ofgas turbines. These applicationsincludejet aircraft, helicopters, large ships andelectric generators.

Internal Combustion Engine-Bhavin

Documents

Transcript of Internal Combustion Engine-Bhavin