Vaporization of JP-8 Jet Fuel in a Simulated Aircraft Fuel Tank ...

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Temperature, Deg. F. 140 120 100 80 60 40 20 0 0 500 1000 1500 2000 2500 3000 Time, seconds Average Liquid Temp Average Surface Temp Average Ullage Temp Measured THC Figure 6.1. Average measured fuel tank temperatures and measured total hydrocarbon concentration for a heated fuel tank at sea level, constant ambient conditions. Mass, kg 0.025 0.02 0.015 0.01 0.005 0 -0.005 Evaporated Condensed Stored Vented Out 0 500 1000 1500 2000 2500 3000 Time, seconds Figure 6.2. Calculated temporal mass transport occurring within the fuel tank for a heated fuel tank at sea level, constant ambient conditions. 6.1.2 Heated Fuel Tank Under Varying Ambient Conditions Measured data for the second example, the case of an aircraft climbing, cruising, and descending from 30,000’ altitude is shown in figure 6.3. Figure 6.4 shows the calculated temporal variation of the mass of fuel evaporated, condensed, stored, and vented out. 2 1.5 1 0.5 0 % Propane Equivalent 49
In the beginning of the test, the liquid fuel was heated to 30°F above its initial temperature and allowed to vaporize until quasi-equilibrium is achieved. From figure 6.4, it can be seen that the amount of fuel evaporated was similar to the amount of fuel stored in the ullage, because at this point there was little condensation. Once dew point conditions were reached, the condensation rate increased and the mass of fuel stored in the ullage leveled off even though the mass of fuel evaporated still increased, as it did for the duration of the test. As the climb to altitude was initiated, the mass of fuel stored in the ullage began to decrease rapidly as ullage gas was vented due to the pressure differential between the ullage and the atmosphere. The ambient air temperature was decreasing quite rapidly at this point due to the increasing altitude, and the fuel tank temperatures began to decrease, causing an increase in the rate of condensation and a decrease in the mass of fuel stored in the ullage. Upon descending from cruise, air entered through the vents due to the pressure differential and diluted the ullage vapor mixture. When the fuel tank was back to sea level atmospheric pressure, the fuel tank temperatures were about 15°F cooler than at the beginning of the test, and the mass of fuel stored in the ullage was about 0.002 kg less than at the beginning. 50
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DOT/FAA/AR-TT09/42 Air Traffic Orga
Page 3 and 4:
1. Report No. DOT/FAA/AR-TT09/42 4.
Page 5 and 6:
ABSTRACT OF THE THESIS VAPORIZATION
Page 7 and 8:
DEDICATION This thesis is dedicated
Page 9 and 10:
5.0 RESULTS 32 5.1 Validation Tests
Page 11 and 12: 5.7 JP-8 fuel vaporization at sea l
Page 13 and 14: LIST OF TABLES Table Page 2.1 Compa
Page 15 and 16: develop procedures to lessen the li
Page 17 and 18: When it was determined that a CWT e
Page 19 and 20: 1.3 Objectives of the Thesis The ul
Page 21 and 22: has more additives, such as an anti
Page 23 and 24: equilibrium is dynamic in nature, b
Page 25 and 26: factor in making these calculations
Page 27 and 28: Volume Fraction, % 30 25 20 15 10 5
Page 29 and 30: 0.035±0.004 at 0°C [26]. The publ
Page 31 and 32: Raleigh numbers which were of order
Page 33 and 34: loading of fuel and be subjected to
Page 35 and 36: pressures. The heaters in the pump
Page 37 and 38: Figure 3.1. View of top surface of
Page 39 and 40: the tank and the ullage vapor conce
Page 41 and 42: attempted, but provided inaccurate
Page 43 and 44: pump that could draw samples from a
Page 45 and 46: 5.0 RESULTS When inputting the expe
Page 47 and 48: etween measured and predicted value
Page 49 and 50: 5.1.2 Isooctane Fuel Vaporization T
Page 51 and 52: higher altitudes, as continuous sam
Page 53 and 54: Temperature, Deg. F. 140 120 100 80
Page 55 and 56: Temperature, Deg. F. 70 60 50 40 30
Page 57 and 58: % Propane Equivalent 2 1.5 1 0.5 0
Page 59 and 60: % Propane Equivalent 3 2.5 2 1.5 1
Page 61: liquid fuel the mass of fuel evapor
Page 65 and 66: 6.2 Flammability Assessment 6.2.1 F
Page 67 and 68: average measured liquid temperature
Page 69 and 70: Fuel to Air Mass Ratio 0.05 0.045 0
Page 71 and 72: 6.2.2 Fuel Tank Under Varying Ambie
Page 73 and 74: Fuel to Air Mass Ratio 0.045 0.04 0
Page 75 and 76: Fuel to Air Mass Ratio 0.05 0.04 0.
Page 77 and 78: temperature measurements would be r
Page 79 and 80: Which is appropriate for Raleigh nu
Page 81 and 82: d dt ( mg c pgTg ) = hb Ab ( Tb −
Page 83 and 84: APPENDIX C: EXPERIMENTAL FUEL FLASH
Page 85 and 86: 13. Fuel Flammability Task Group, A
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Vaporization of JP-8 Jet Fuel in a Simulated Aircraft Fuel Tank ...

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