PISTONE ENGINE (MIDTERM) 1

Question 1

Methods of Gasoline Production:

Answer 1

• Fractional Distillation
• Cracking
• Polymerization and hydrogenation
• Alkylation

Question 2

Is the oldest method
for gasoline production. It generates what is
referred to as straight run gasoline.

Answer 2

Fractional Distillation

Question 3

Is a process
whereby heavy
hydrocarbons are broken
down or ____ to
elevate the quantity of
gasoline derived from a
barrel of crude oil.

Answer 3

Cracking

Question 4

• Polymerization and hydrogenation - During polymerization light hydrocarbons,
such as ethylene, propylene, and butylene, are combined to make heavier
hydrocarbons.
• The hydrogenation process adds hydrogen to the polymer fuel. The result is
isooctane fuel with a rating of 100.

Question 5

Is a process where gaseous hydrocarbons are converted into liquid
hydrocarbons.

Answer 5

Alkylation

Question 6

One critical specification that aviation gasoline must adhere to is its ________

Answer 6

octane rating or performance number

Question 7

If an engine is burning a gasoline below its designed rating, the engine will
experience _____

Answer 7

Detonation

Question 8

Common additives of AVGAS

Answer 8

• Tetra-ethyl or alkyl-lead
• Anti knock additives
• Metal de-activators
• Color dyes
• Oxidation inhibitors
• Corrosion inhibitors
• Icing inhibitors
• Static dissipaters

Question 9

Aircraft fuels generally consist of approximately ____ carbon and ____ hydrogen,
which are linked together to provide a substance known as hydrocarbon.

Answer 9

85% and 14%

Question 10

When mixed with air (____ oxygen and ___ nitrogen) and burned within the
engine cylinders, these hydrocarbons combines with the oxygen to form carbon
dioxide and water vapor.

Answer 10

21% and 79%

Question 11

The nitrogen remains _____, but its presence is most important for it acts
as a buffer reducing the violence of the explosive combustion.

Answer 11

Unchanged

Question 12

Has excellent anti-knocking properties. Fuels with the same anti-
knocking properties as iso-octane are given a rating of 100.

Answer 12

Iso-Octane

Question 13

Has poor anti-knocking properties which mixed with iso-octane in
varying amounts to give the reference fuel an octane rating. Heptane is used to set
the standard zero point.

Answer 13

Heptane

Question 14

This is a measure of the amount of heat that can be obtained
from fuel and is measured in thermal units or per pounds.

Answer 14

Calorific value

Question 15

This is the tendency for the fuel to evaporate or burn quickly.
Problem with high volatility is vapor locking.

Answer 15

Votality

Question 16

Volatility : This is the tendency for the fuel to evaporate or burn quickly.
Problem with high volatility is ________

Answer 16

Vapor Locking

Question 17

Aircraft fuel is rated for its anti-knock value. This value is
expressed as an octane number or rating

Answer 17

Anti-knock Properties

Question 18

Classification of fuels :

Answer 18

• SOLID
• LIQUID
• HYPERGOLIC
• GASEOUS

Question 19

Are mostly used for rocket-type engines. Solid fuel rocket
engines are frequently used to help an aircraft accelerate during takeoff.

Answer 19

Solid Fuels

Question 20

Are unique liquid fuels in that they combust upon contact
with each other. No source of ignition is required to trigger the reaction.

Answer 20

HYPERGOLIC FUELS

Question 21

They contain a useful energy level for volume and weight and
are well-suited for general, commercial, and military aviation.

Answer 21

LIQUID FUELS

Question 22

Are not well suited for aviation purposes. Due to the
relatively low energy content of gaseous fuels, such as natural gas, this option is
not a practical product for use in aviation.

Answer 22

GASEOUS FUELS

Question 23

which is largely kerosene,
contains less heat energy than
gasoline by weight, but more heat
energy than gasoline by volum

Answer 23

Jet fuel

Question 24

has good lubricity and does
not evaporate as readily as gasoline.

Answer 24

Jet fue

Question 25

gasoline is
a gas cheaper than avgas
used in light experimental
aircraft engines.

Answer 25

Mogas or motor

Question 26

can be a substitute
to avgas.

Answer 26

Mogas

Question 27

Aviation Fuel - Qualities and Requirements

Answer 27

• Anti-Knock Rating
• Volatility
• Vapor lock
• Oil dilution
• Corrosion
• Performance number

Question 28

can occur if the boiling point of the fuel is too high.

This is because any unburnt fuel will pass into the engine if incorrect
evaporation has taken place.

Answer 28

Oil dilution

Question 29

these elements are caused by the Sulphur
and additives content of the fuel.

Answer 29

Corrosion

Question 30

is a mixture of fuel and air containing more air
than fuel.

Answer 30

Lean mixture

Question 31

is a mixture of fuel and air containing more fuel
than air.

Answer 31

Rich mixture

Question 32

Possesses a high anti-knock value

Answer 32

Iso-Octane

Question 33

Has low anti-knock value

Answer 33

Heptane

Question 34

Aviation gasoline (Avgas) possesses anti-knock qualities greater than 100 octane or it is now a

Answer 34

Pure Iso-Octane

Question 35

• In 1921, automotive engineers working for
General Motors discovered that tetraethyl lead
(better known as lead) provided octane to
gasoline, preventing engine knock.
• Is a kind of “octane booster” that if added in a
fuel increases its octane rating.
• If octane produced by pure fuel is 100 % then
the addition of lead might let the octane
increase up to 145 %, thus the performance
number is 145.
Disadvantage:
• Contributes to air pollution