Pulse Detonation Engine Thrust Tube Heat Exchanger for Flash Vaporization and Supercritical Heating of JP-8

摘要

Research has shown that performance of liquid hydrocarbon fueled pulse detonation engines is limited by the time required to evaporate liquid fuel droplets within the mixture. Vaporization of liquid fuels prior to injection has been shown to decrease ignition times and also increases fuel efficiency; however, the size and efficiency of the vaporization system used are not feasible for use in future pulse detonation aircraft concepts. The purpose of this research is to harness the waste heat of pulse detonation engine thrust tubes to generate a steady-state, self-sustained flash vaporization and supercritical heating system using JP-8 as the working fluid and fuel. Using a pulse detonation engine thrust tube mounted heat exchanger, the successful flash vaporization of JP-8 has been demonstrated. Additional testing demonstrated the successful heating of JP-8 to supercritical conditions with fuel injection temperatures over 760 K. All JP-8 flash vaporization and supercritical heating tests were sustained by the heated fuel and run to steady- state conditions. Heat addition rates to the fuel of up to 7.7 kW were achieved during superheated testing. A method for experimentally determining supercritical fluid density is presented based on the findings of the supercritical heating tests.