Thermal Modeling for the Sustained Hypersonic Flight Experiment

Abstract

This paper details the development, validation and use of a thermal model created for the UK Ministry of Defence funded Sustained Hypersonic Flight Experiment (SHyFE). This compact ramjet will operate at Mach 4 to 6 leading to very high air ∞ow stagnation temperatures. The thermal management system must be designed to maintain the avionics and fuel system at acceptable temperatures throughout the ∞ight. The heat exchange mechanisms were predicted throughout the acceleration section of the Onal SHyFE ∞ight experiment using a thermal resistance network approach which incorporates convection, radiation and conduction. This allowed the SHyFE thermal management system to be assessed at an early design stage before the vehicle geometry was Onalised and before detailed CAD models were available. The resulting thermal model is highly ∞exible which allows changes in geometry to be easily incorporated and assessed. The thermal model of the SHyFE vehicle during ∞ight was validated using SHyFE Mach 4 combustion ground test surface temperature measurements. The ∞exibility of the model allowed the combustion chamber and nozzle ground experiment thermal systems to be predicted using the same methodology as the ∞ight experiment. The predicted combustor exit gas temperatures show good agreement with the measured ground experiment exit gas temperatures providing conOdence in the thermal modelling technique. The Mach 4 combustion test thermal models were used to aid the design of the ground experiment cooling water system and to assess the reliability of experiment high temperature instrumentation. The SHyFE ∞ight thermal model was used to assess the suitability of a range of ∞ameholder designs by predicting the nozzle heat ∞ow and surface temperatures for each design.