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Robert Ian Ochs Rutgers, The State University of New Jersey. International Aircraft Systems Fire Protection Working Group Meeting Atlantic City, New Jersey November 5, 2003.
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Robert Ian Ochs Rutgers, The State University of New Jersey International Aircraft Systems Fire Protection Working Group Meeting Atlantic City, New Jersey November 5, 2003 Jet-A Vaporization In an Experimental TankPart II: Experimental Results at Atmospheric and Sub-Atmospheric Pressures
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 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
Conclusions and Future Work • Complete verification at lower pressures (6.9 psia and below) • Use existing flight data to simulate entire flight profiles