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

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2.1 Jet Fuels 2.1.1 History of Jet Fuel 2.0 REVIEW OF LITERATURE Jet fuels have changed significantly over the last sixty years. The first British jet engine, patented by Sir Frank Whittle in 1930 and first flown in 1941, was designed to run on illumination kerosene, as gasoline was in short supply during World War II [14]. The first U.S. jet engines were direct copies of this original design, and adopted kerosene as well for the primary fuel in U.S. jet turbines. The first U.S. jet fuel specification, AN-F- 32, was made in 1944 and was designated JP-1, a kerosene with a flashpoint of 109°F and freeze point of -77°F [14]. JP-1 had limited availability, and was soon replaced by wide cut fuels, which are mixtures of hydrocarbons that span the gasoline and kerosene boiling point ranges [14]. The military version of the wide cut fuel, JP-4, was used by the U.S. military from 1951 to 1995, and the commercial equivalent Jet-B was used in airliners. The wide cut fuel had a flash point of about 0°F and freeze point of -77°F. This low flash point indicates that the wide cut fuels were quite volatile, like gasoline, which has a flash point of about -40°F, and that the risk of fire during fuel handling and crash was great, as were evaporative losses at altitude. It was for these reasons that a non-wide cut fuel was sought with a higher flashpoint temperature for safety and a higher freeze point temperature for wider availability. The specifications for Jet-A and Jet-A1 were made in the 1950’s for commercial use, and have a minimum flashpoint specification of 100°F and freeze points of -40°F and –47°F, respectively. The U.S. military equivalent of Jet-A is JP-8, and has been in use since the changeover from wide cut JP-4 in 1995. JP-8 is very similar to Jet-A but 7
has more additives, such as an antistatic additive and an icing inhibitor [15]. Table 2.1, with information from ref. [14] and [15], shows a comparison of the flash and freeze points of the various fuels from over the years. Table 2.1. Comparison of Aviation Turbine Fuel Properties Fuel Min. Flash Max Freeze Type Point (°F) Point (°F) Years in Use JP1 109 -77 1944-47 JP4 0 -77 1951-95 JP5 140 -51 1952-present JP6 140 -66 1956(XB-70) JP7 140 -47 1960's(SR-71) JP8 100 -53 1978-present Jet A 100 -40 1950's-present Jet A-1 100 -47 1950's-present ASTM D 1655 is the current standard that lists the specifications for three types of jet fuels: kerosene based Jet-A, Jet A-1 and the wide cut Jet-B. There are at least 23 specifications for Jet-A, which set maximum and minimum limits for stated properties or measurements [13]. These specifications, however, do not require an exact composition of chemical species (Jet-A has hundreds of different components); rather, they specify that “aviation turbine fuel shall consist of refined hydrocarbons derived from crude petroleum, natural gasoline, or blends thereof with synthetic hydrocarbons [16].” Since exact composition is not required, Jet-A and the military grade equivalent JP-8 can typically consist of hundreds of compounds. Analysis has shown that Jet-A consists of about “75%-85% paraffin, both straight chain and cyclic, with the balance almost entirely aromatic compounds” [13]. 8
Page 1 and 2: 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: 1.3 Objectives of the Thesis The ul
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 and 62: liquid fuel the mass of fuel evapor
Page 63 and 64: In the beginning of the test, the l
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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