Design of a High Heat Flux Facility for Thermal Stability Testing of Advanced Hydrocarbon Fuels

Abstract

With both the Air Force and NASA interested in developing reusable hydrocarbon-fueled engine technologies for reusable launch vehicles, there is an increased need to better understand the thermal stability of hydrocarbon fuels under high heat fluxes encountered during regenerative cooling. Currently, no existing thermal stability test rig can accurately simulate the high heat flux conditions that will exist in the cooling channels of these new high-pressure hydrocarbon engines. To meet the high reliability and reusability requirements proposed for these engines, the Air Force Research Laboratory (AFRL) has designed a High Heat Flux Facility (HHFF) using experience gained from past and present thermal stability test rigs. CFD++, a Metacomp Technologies Inc. computational fluid dynamics software suite, was employed to optimize the design prior to manufacture. Conjugate heat transfer calculations were performed in a single computational domain containing the copper heater block and the fluid channel of the new test rig design. The first tests conducted in the facility will be highly instrumented and will be used to validate the CFD++ calculations. The parameters of interest for a given geometry are the heat transfer coefficient, the degree of coking and corrosion in the channel, and the pressure drop as functions of heat flux, wall temperature, Reynolds number, channel material, fuel composition and pressure. The HHFF will be an important tool to facilitate the development and transition of new advanced hydrocarbon fuels under study by AFRL.