Jet-A Vaporization In an Experimental Tank

Part II: Experimental Results at Atmospheric and Sub-Atmospheric Pressures

Robert Ian OchsRutgers, The StateUniversity of NewJersey

International Aircraft Systems Fire ProtectionWorking Group MeetingAtlantic City, New JerseyNovember 5, 2003

Fuel Flammability Prediction

• Computational model written by Professor Polymeropoulos of Rutgers University

• Uses principles of heat and mass transfer to predict vapor composition

Overview

• Fuel vaporization experimentation is performed at W.J.H. Technical Center at Atlantic City Airport, NJ

• Experimental data consists of hydrocarbon concentrations and temperatures as functions of time

• Data is input into computer model and compared to calculated vapor composition

Model Inputs

• Liquid fuel, tank surface temperature profiles

• Pressure and outside air temperatures as functions time

• Fuel composition (volume fractions of C5-C20 Alkanes) from Woodrow (2003)

• Tank dimensions and fuel loading

Model Outputs

• Hydrocarbon concentration profile

• Ullage temperature profile

Experimental Setup• Fuel tank – 36”x36”x24”, ¼” aluminum• Sample ports

– Heated hydrocarbon sample line– Pressurization of the sample for sub-atmospheric pressure

experiments– Intermittent (at 10 minute intervals) 30 sec long sampling

• FID hydrocarbon analyzer, cal. w/2% propane• 12 thermocouples • Blanket heater for uniform floor heating• Unheated walls and ceiling• JP-8 Fuel

Experimental Setup (continued)

• Fuel tank inside environmental chamber– Programmable variation of chamber pressure

and temperature using:• Vacuum pump system

• Air heating and refrigeration system

Experimental Setup (continued)

Thermocouple Locations

Experimental Procedure• Fill tank with specified quantity of fuel• Adjust chamber pressure and temperature to desired

values, let equilibrate for 1-2 hours• Begin to record data with DAS• Take initial hydrocarbon reading to get initial quasi-

equilibrium fuel vapor concentration• Set tank pressure and temperature as well as the

temperature variation• Experiment concludes when hydrocarbon

concentration levels off and quasi-equilibrium is attained

Experimental Results-Sea Level

Constant Pressure, Sea Level

0

5000

10000

15000

20000

25000

30000

0 1000 2000 3000 4000 5000

Time, s

pp

m C

3H8

0

20

40

60

80

100

120

Te

mp

era

ture

, F

Experimental HCFuel Type 1Fuel Type 2TLIQ

125 F.P.120 F.P.

Fuel Temperature

Experimental Results-10,000 ft.

Constant Pressure, 10,000 ft.

0

10000

20000

30000

40000

50000

0 1000 2000 3000 4000 5000

Time, s

pp

m C

3H8

0

20

40

60

80

100

120

140

Te

mp

era

ture

, F

Experimental HCFuel Type 1Fuel Type 2TLIQ

Experimental Results-20,000 ft.

Constant Pressure, 20,000 ft.

0

10000

20000

30000

40000

50000

60000

0 1000 2000 3000 4000 5000

Time, s

pp

m C

3H8

0

20

40

60

80

100

120

Te

mp

era

ture

, F

Experimental HCFuel Type 1Fuel Type 2TLIQ

Experimental Results Pressure and Temperature Variation

Pressure and Temperature Variation

0

5

10

15

20

0 5000 10000 15000

Time, s

Pre

ssur

e, p

sia

0

20

40

60

80

100

Tem

pera

ture

, F

PRESSURE

TLIQ

Experimental Results-Hydrocarbon Profiles

Hydrocarbon Comparison

0

5000

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15000

20000

25000

0 5000 10000 15000

Time, s

pp

m C

3H8

Experimental HCCalculated HC

Cooling

Pressure Drop

Heating

Conclusions and Future Work

• Complete verification at lower pressures (6.9 psia and below)

• Use existing flight data to simulate entire flight profiles