Jet Fuel Characteristics

8/11/2019 Jet Fuel Characteristics

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Jet Fuel CharacteristicsJet Fuel Characteristics

Performance Engineer OperationsFlight Operations Engineering

Dave Lawicki

Performance Engineer OperationsFlight Operations Engineering

Dave Lawicki

May 2002May 2002


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Why this Subject?Why this Subject?

Provide a brief introduction to aviation fuel

definitions and characteristics Familiarize you with terminology and industry

jargon

Address operational concerns related to fuel Inform you of research work and possible future

fuels

Exchange some insight into the Energy of Flight

Provide a brief introduction to aviation fuel

definitions and characteristics Familiarize you with terminology and industry

jargon

Address operational concerns related to fuel Inform you of research work and possible future

fuels

Exchange some insight into the Energy of Flight


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TopicsTopics

Oil Distillation

Types of Aviation Fuel Specifications

Composition of Fuel Fuel Properties

Non-Normal Situations

Alternative Fuels

Oil Distillation

Types of Aviation Fuel Specifications

Composition of Fuel

Fuel Properties

Non-Normal Situations

Alternative Fuels


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Distillation of Crude OilDistillation of Crude Oil

Diesel fuelDiesel fuel

CokeCokeSulfur Sulfur Bunker oilBunker oil

LPGLPG

Jet fuel (about 5 U.S. gallons)Jet fuel (about 5 U.S. gallons)

Co-generationCo-generation

GasolineGasoline

1 Barrel of Crude = 42 U.S. gallons1 Barrel of Crude = 42 U.S. gallons


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Types of Aviation FuelTypes of Aviation Fuel

Aviation Gasoline - AvGas

Turbine Fuels

Aviation Gasoline - AvGas

Turbine Fuels


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Aviation Gasoline (AvGas)Aviation Gasoline (AvGas)

Reciprocating Engines Only

Rated by Octane - 80/87, 100/130,115/145 - Red, Blue, Purple

Commercial Specification -ASTM D 910

Reciprocating Engines Only

Rated by Octane - 80/87, 100/130,115/145 - Red, Blue, Purple

Commercial Specification -ASTM D 910


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Turbine FuelsTurbine Fuels

Jet A Kerosene Type,freeze point -40C (U.S.domestic only)

Jet A-1 Kerosene Type,freeze point -47C

Jet B Wide Cut, freeze

point -50C

Jet A Kerosene Type,freeze point -40C (U.S.domestic only)

Jet A-1 Kerosene Type,freeze point -47C

Jet B Wide Cut, freezepoint -50C

Commercial GradesCommercial Grades


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JP-4 Wide Cut, similar to Jet B JP-5 Higher flash point for carrier

operations

JP-7 Thermally Stable for SR-71higher temperatures

JP-8 Kerosene Type, similar to

Jet A-1 JP-9 Missile fuel (higher energy

per unit volume)

JP-4 Wide Cut, similar to Jet B

JP-5 Higher flash point for carrieroperations

JP-7 Thermally Stable for SR-71higher temperatures

JP-8 Kerosene Type, similar to

Jet A-1 JP-9 Missile fuel (higher energy

per unit volume)

Military Grades (U.S.)Military Grades (U.S.)


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Commercial Turbine FuelCommercial Turbine Fuel

Industry/Governmentspecifications

American Society forTesting and Materials(ASTM)

Industry/Governmentspecifications

American Society forTesting and Materials(ASTM)

ASTM D1655 Jet A, Jet A-1, Jet BASTM D1655 Jet A, Jet A-1, Jet B

SpecificationsSpecifications


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Commercial Turbine FuelCommercial Turbine FuelSpecificationsSpecifications


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Commercial Turbine FuelCommercial Turbine Fuel

International Air TransportAssociation (IATA guidance material)IATA ADD76-1 Kerosene Types andWide Cut

Aviation Fuel Quality Requirementsfor Jointly Operated Systems(AFQRJOS) Check List, Jet A-1, Jet B(non-U.S.)

International Air TransportAssociation (IATA guidance material)IATA ADD76-1 Kerosene Types andWide Cut

Aviation Fuel Quality Requirementsfor Jointly Operated Systems(AFQRJOS) Check List, Jet A-1, Jet B(non-U.S.)

Specifications (cont.)Specifications (cont.)


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British - DERD.2494 (AVTUR) Canadian - CAN/CGSB 3.23-M86

French - AIR 3405/C

Russian - GOST 10227-86 T-1, TS-1(TS-1 freeze point -50 to -60C)

Romanian - 3754/73, CS-3, STAS 5639

British - DERD.2494 (AVTUR) Canadian - CAN/CGSB 3.23-M86

French - AIR 3405/C

Russian - GOST 10227-86 T-1, TS-1(TS-1 freeze point -50 to -60C)

Romanian - 3754/73, CS-3, STAS 5639

Kerosene TypesKerosene TypesJet A-1 SpecificationsJet A-1 Specifications


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Wide CutWide Cut

British - DERD.2486 (AVTUR)

Canadian - CAN/CGSB 3.22-M86

French - AIR 3407/B

Russian - GOST 10227-86, T-2 German - TL 9130-006 Issue 6

British - DERD.2486 (AVTUR)

Canadian - CAN/CGSB 3.22-M86

French - AIR 3407/B

Russian - GOST 10227-86, T-2 German - TL 9130-006 Issue 6

Jet B SpecificationsJet B Specifications


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Engine ManufacturesEngine Manufactures

General Electric - SpecificationNo. D50TF2

Pratt & Whitney - Service BulletinNo. 2016

Rolls-Royce - Appendix 2 to EngineOperating Manual

FAA/JAA Approved Airplane FlightManual

General Electric - SpecificationNo. D50TF2

Pratt & Whitney - Service BulletinNo. 2016

Rolls-Royce - Appendix 2 to EngineOperating Manual

FAA/JAA Approved Airplane FlightManual

SpecificationsSpecifications


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Airplane Flight ManualAirplane Flight Manual


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Turbine Fuel CompositionTurbine Fuel Composition

Four groups of Hydrocarbons in Jet Fuel:Four groups of Hydrocarbons in Jet Fuel:

HH

HH HH HH HH HH

HHCC CC CC CC CC

HH HH HH HH HH

Paraffins, Isoparaffins, Cycloparaffins Paraffins, Isoparaffins, Cycloparaffins

Aromatics Aromatics

Naphthalenes Naphthalenes

Olefins Olefins


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Other Fuel ConstituentsOther Fuel Constituents

Sulfur - corrosion and emissions

Gums - filter clogging andsticky valves

Water - corrosion and filter clogging

Naphthenic Acid - corrosion

Sulfur - corrosion and emissions

Gums - filter clogging andsticky valves

Water - corrosion and filter clogging

Naphthenic Acid - corrosion


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Fuel AdditivesFuel Additives

Approved Additives only

Antioxidents Metal Deactivators

Fuel System Icing Inhibitors

Corrosion Inhibitors

Static Dissipators

Approved Additives only

Antioxidents Metal Deactivators

Fuel System Icing Inhibitors

Corrosion Inhibitors

Static Dissipators


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Turbine Fuel PropertiesTurbine Fuel Properties

Density (Specific Gravity SG)

Lower Heating Value (LHV)

Viscosity

Lubricity

Low Temperature

Volatility

Electrical

Bulk modulus

Thermal Oxidation Stability

Material Compatibility

Toxicity

Density (Specific Gravity SG)

Lower Heating Value (LHV)

Viscosity

Lubricity

Low Temperature

Volatility

Electrical

Bulk modulus

Thermal Oxidation Stability

Material Compatibility

Toxicity

Fuel PropertiesFuel Properties


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Density, Specific GravityDensity, Specific Gravity

Density = Mass/Volume

Specific Gravity (SG) also known as RelativeDensity

Typical Jet A, Jet A-1: SG = 0.815

Typical Jet B: SG = 0.764 Varies with temperature API = (141.5/SG) - 131.5 SG measured with hydrometer per

ASTM D1298 Airplane Densitometers

Density = Mass/Volume

Specific Gravity (SG) also known as RelativeDensity

Typical Jet A, Jet A-1: SG = 0.815

Typical Jet B: SG = 0.764 Varies with temperature API = (141.5/SG) - 131.5

SG measured with hydrometer per ASTM D1298

Airplane Densitometers



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Lower Heating Value (LHV)Lower Heating Value (LHV)

LHV = Net Heat of Combustion (BTU/lb)

Jet A: 18,484 - 18,645 (ave. 18564) Density relationship to LHV

Performance analysis based on18,580 BTU/lb

Boeing Airplane Performance Monitoringprogram (APM) input

LHV = Net Heat of Combustion (BTU/lb)

Jet A: 18,484 - 18,645 (ave. 18564) Density relationship to LHV

Performance analysis based on18,580 BTU/lb

Boeing Airplane Performance Monitoringprogram (APM) input



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APM Program DocumentationAPM Program Documentation Fuel PropertiesFuel Properties


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Fuel Lower Heating Value EstimationFuel Lower Heating Value Estimation Fuel PropertiesFuel Properties


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ViscosityViscosity

Fuel line pressure drop and

pumping capabilities Low temperatures increase

viscosity

Measuring units areCentistokes (mm /sec)

Fuel line pressure drop and

pumping capabilities Low temperatures increase

viscosity

Measuring units areCentistokes (mm /sec)



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Fuel LubricityFuel Lubricity

Controls, valves, bearing, pumps

Low viscosity preventshydrodynamic film

Absorbs into surface - Boundarylayer lubricants

Refining removes lubricants(thermally stable fuels, SR-71)

Corrosion inhibitors augment Lubricity

Controls, valves, bearing, pumps

Low viscosity preventshydrodynamic film

Absorbs into surface - Boundarylayer lubricants

Refining removes lubricants(thermally stable fuels, SR-71)

Corrosion inhibitors augment Lubricity



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Low Temperature PropertiesLow Temperature Properties

Freeze Point (wax crystals disappear)

Pour Point (1.5 inch cylinder test)(4C to 20C below Freeze Point)

Cloud Point (haze forms)

Fuel will not flow when indicatedtemperature is below pour point

Fuel starts to solidify when recoverytemperature is below pour point

Operational Considerations

Freeze Point (wax crystals disappear)

Pour Point (1.5 inch cylinder test)(4C to 20C below Freeze Point)

Cloud Point (haze forms)

Fuel will not flow when indicatedtemperature is below pour point

Fuel starts to solidify when recoverytemperature is below pour point

Operational Considerations



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Operational ConsiderationsOperational Considerations

Pilots must maintain fuel temperature at least 3Cabove fuel freeze point

Low temperature operations is a concern for fueltransfer, boost pump inlets and in fuel lines

The rate at which the fuel temperature declines is

a function of air temperature, airplane geometry,fuel management schedule and time

Fuel temperature will approach the recovery

temperature Recovery Temperature is slightly lower than TAT

TAT and Recovery Temperature are a function ofambient air temperature and Mach

Pilots must maintain fuel temperature at least 3Cabove fuel freeze point

Low temperature operations is a concern for fueltransfer, boost pump inlets and in fuel lines

The rate at which the fuel temperature declines is

a function of air temperature, airplane geometry,fuel management schedule and time

Fuel temperature will approach the recovery

temperature Recovery Temperature is slightly lower than TAT

TAT and Recovery Temperature are a function ofambient air temperature and Mach



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Lowest Fuel TemperaturesLowest Fuel Temperatures

F u e

l T e m p e

r a t u r e

C

Initial fuel temperature = +5C

Jet A Freeze Point

Minimum Recovery Temperature

Jet A-1 Freeze Point

Range-Nautical Miles

Initial fuel temperature = -18C

74710

0

-10

-20

-30

-40

-50

-60

0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 5,000

C A L C

C H E

C K

A P R

A P R

F U E

C A P Y

R E V I S E D

D A T E

D 6 - 4 2 3 8 6

F I G . 3 5

P A

G E 1 3 A

L O WE

S T F

U E L T E M P E R A

T U R E

S I N

O U T B

O A R D M A I N T A N K

S O F 7 4 7 A

S A

F U N

C T I O N

O F R A N

G E

T H E B

O E I N

G C O M P

A N Y



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Increasing use of Polar RoutesIncreasing use of Polar Routes Fuel PropertiesFuel Properties

Hong Kong

Chicago

UnitedStates

Canada

Russia

Mongolia

China ArcticOcean

PacificOcean

Japan

777 Demonstration Flight:15 hours 22 minutes total flight timeAt 10 hours into the flight, OAT = -64C, TAT = -35C,Recovery Temp = -38C. The lowest fuel temperature was-32C at 11 hours into the flight.

777 Demonstration Flight:15 hours 22 minutes total flight timeAt 10 hours into the flight, OAT = -64C, TAT = -35C,Recovery Temp = -38C. The lowest fuel temperature was-32C at 11 hours into the flight.


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Actual Fuel vs. SpecificationActual Fuel vs. Specification

Specification: Jet A -40C, Jet A-1 -47C,Jet B -50C

Freeze Point of actual fuel varies from day-to-dayand airport-to-airport

Actual delivered fuel might have freeze point asmuch as 40% better than specification

Pilot must observe specification value unless testresults are known

Specification: Jet A -40C, Jet A-1 -47C,Jet B -50C

Freeze Point of actual fuel varies from day-to-dayand airport-to-airport

Actual delivered fuel might have freeze point asmuch as 40% better than specification

Pilot must observe specification value unless testresults are known



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Operational Response to Cold FuelOperational Response to Cold Fuel

Increase Mach (.01 Mach is 0.5C)

Divert around cold air mass

Descend to lower (warmer) altitude(extreme cases may require 25,000 ft at .85 Mach)

Dispatch with known fuel freeze point

Increase Mach (.01 Mach is 0.5C)

Divert around cold air mass

Descend to lower (warmer) altitude(extreme cases may require 25,000 ft at .85 Mach)

Dispatch with known fuel freeze point



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Cold Fuel Flow ResearchCold Fuel Flow Research Fuel PropertiesFuel Properties

Bay 1Bay 2

Thermocouplerake

Thermocouple

rakes

Boost pumpinlet

Flapper valves


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0

35

-100 -80 -60 -40 -20 0

90 min450 min 2 min

Temperature ( o F)

Low-convection,mushy zone

Bulk tank temperature(airplane probe)

H e i g h

t a b o v e t a

n k b o t

t o m

( i n c h

e s )

Fuel pour point

102 < q total < 103 W/m 2

with

20 W/m2

latentheat release

qtotal 30 W/m 2

Fuel PropertiesFuel PropertiesCold Fuel Flow ResearchCold Fuel Flow Research


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Cold Fuel SummaryCold Fuel Summary

Fuel Tank tests at cold temperatures

Computer Models of tank cooling - FuelTemperature Prediction Program (FTPP)

IATA is reviewing ASTM/GOST testing procedures

Fuel additives being considered

Fuel Freeze points are being monitored in U.S.

IATA team to audit fuel quality around the world Future system to monitor fuel freeze points at

airports on-line, real time. (Phase Technology)

Fuel Tank tests at cold temperatures

Computer Models of tank cooling - FuelTemperature Prediction Program (FTPP)

IATA is reviewing ASTM/GOST testing procedures

Fuel additives being considered

Fuel Freeze points are being monitored in U.S.

IATA team to audit fuel quality around the world Future system to monitor fuel freeze points at

airports on-line, real time. (Phase Technology)



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VolatilityVolatility

Tendency to change from liquid

to vapor Reid vapor pressure

Relative to Jet A-1 at 60F:

Jet B vapor pressureis 1,750% higher

AvGas vapor pressureis 4,600% higher

Tendency to change from liquid

to vapor Reid vapor pressure

Relative to Jet A-1 at 60F:

Jet B vapor pressureis 1,750% higher

AvGas vapor pressureis 4,600% higher



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ElectricalElectrical

Dielectric constant

(fuel quantity) Electrical Conductivity

Dielectric constant

(fuel quantity) Electrical Conductivity



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Flammability and IgnitionFlammability and Ignition

Flammabilityvs. Altitude

Flash Point

Flammabilityvs. Altitude

Flash Point

CharacteristicsCharacteristics



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Bulk ModulusBulk Modulus

Fuel is used as hydraulic fluid in

servo valves Jet A-1: 193 kpsi

Airplane hydraulic fluid (Skydrol):210 kpsi

Fuel is used as hydraulic fluid in

servo valves Jet A-1: 193 kpsi

Airplane hydraulic fluid (Skydrol):

210 kpsi



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Thermal Oxidation StabilityThermal Oxidation Stability

Gums and Deposits

Fuel additives to reduce thermaldegradation(thermally stable fuels only, SR-71)

Commercial grades controlledby specification

Gums and Deposits

Fuel additives to reduce thermaldegradation(thermally stable fuels only, SR-71)

Commercial grades controlledby specification



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Material CompatibilityMaterial Compatibility

Metals

Satisfactory Aluminum and alloys Carbon steels

Stainless steels

Unsatisfactory

Bronze Nickel Copper

Zinc Cadmium

Metals

Satisfactory Aluminum and alloys Carbon steels

Stainless steels

Unsatisfactory

Bronze Nickel Copper

Zinc Cadmium

Packing and gaskets Satisfactory

Nylon Polyethylene

Packing and gaskets Satisfactory

Nylon Polyethylene

Unsatisfactory Fluorothene

Vinylite

Teflon

Unsatisfactory Fluorothene

Vinylite

Teflon



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ToxicityToxicity

Not highly toxic

Handle with Care

Not highly toxic

Handle with Care



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Non-Normal SituationsMixing of FuelsNon-Normal SituationsMixing of Fuels

Jet A and Jet B - Ok, increased

volatility Mixing Jet A and Jet A-1 raises

freeze point significantly towards

that of Jet A AvGas - Vapor pressure, boil off,

cavitation, fueling dangers, hot

section deposits, lubrication Diesel/heating oils - Cold flow,

viscosity, freeze point

Jet A and Jet B - Ok, increased

volatility Mixing Jet A and Jet A-1 raises

freeze point significantly towards

that of Jet A AvGas - Vapor pressure, boil off,

cavitation, fueling dangers, hot

section deposits, lubrication Diesel/heating oils - Cold flow,

viscosity, freeze point


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Airplane FuelsNet Heat of CombustionAirplane FuelsNet Heat of Combustion

44.644.6

44.444.4

44.244.2

44.044.0

43.843.8

43.643.6

43.443.4

43.043.0

42.842.8

42.642.6

42.442.4

42.242.2

42.042.0

N e

t H e a

t , M J

/ k g

N e

t H e a

t , M J / k g

Av. GasAv. Gas Jet A,Jet A-1Jet A,

Jet A-1JP-5JP-5 JP-7JP-7 Thermally StableThermally StableJet B,

JP-4Jet B,JP-4


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Airplane FuelsVapor PressureAirplane FuelsVapor Pressure


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Future FuelsFuture Fuels

Hydrogen

Methane Synthetic Fuels

(about 4 times more

expensive)

Hydrogen

Methane Synthetic Fuels

(about 4 times more

expensive)


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When The Tank Runs Dry...When The Tank Runs Dry...Alternative FuelsAlternative Fuels

00 66 1212 1818 2424 3030 3636 4242 4848

A pound of hydrogen has almost three times the energy of a poundof conventional fuel.A pound of hydrogen has almost three times the energy of a poundof conventional fuel.

Liquid hydrogen

Liquid methane

Jet fuel

Thousands of BTUsper poundThousands of BTUsper pound

l h


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Questions?Questions?


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J F l Ch i iJet Fuel Characteristics


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Fuel Energy Content Versus Fuel Density (continued)

correction for density and LHV should be made. The LHVcorrection is difficult since The LHV for the particular fuel loadcan only be determined after the flight by laboratory analysis. Itmay be possible, however, to combine density and energyeffects into a single correction, based on Figure 1 variation,which could be referenced to density only. However, this may beunnecessarily complicated, particularly since the fuel density of

the destination airport is probably unknown. Our generalrecommendation on tankering fuel is that this should not be doneunless the price advantage is really significant. This would allowfor unknowns such as wear and tear on airframe, wheels, tires,engines, etc.., and for fuel density and energy content variations.

Documents

Jet Fuel Characteristics