Analysis of a Cylindrical Specimen Heated by an Impinging Hot Hydrogen Jet

摘要

A computational conjugate heat transfer methodology was developed to study the heat transfer inside a cylindrical specimen heated by an impinging hot hydrogen jet for nuclear thermal propulsion applications. The development involved the implementation of a time-marching solid conduction heat transfer procedure onto a transient pressure-based unstructured-grid computational-fluid-dynamics formulation. The conjugate heat transfer between the solid and the gaseous media were anchored with a standard solid heat transfer code. Three steady-state and five transient analyses were then conducted, using thermal conductivities representing three hypothetical composite materials. It was found that material thermal conductivity strongly influences the heat transfer characteristics. In addition, it was observed that during steady-state operations, the specimen experiences a high temperature but a low thermal gradient, whereas during transient operations, the specimen undergoes a high thermal gradient during the initial heating. It was also found from the transient analyses that the shorter the ramp time, the stronger the thermal gradient is experienced by the cylindrical specimen.