Heat transfer in ultra-high temperature advanced ceramics under high enthalpy arc-jet conditions

Aim of this work is to analyze the response of an ultra-high temperature ceramic at typical heat flux conditions of thermal protection systems of a re-entry spacecraft. In particular, a ZrB2-SiC based ultra-high temperature advanced ceramic sharp leading edge demonstrator (1 mm nominal radius of curvature) was manufactured and tested in a non-equilibrium high enthalpy supersonic airflow, 20 MJ/kg of peak total enthalpy, by using an arc-jet ground facility. The surface temperature of the leading edge was monitored by infrared thermo-cameras coupled to a two-color pyrometer. The ultra-refractory advanced ceramic leading edge withstood stressful thermo-chemical loads successfully, without obvious failure. Ad-hoc computational fluid dynamics simulations rebuilt the adopted set-up and related experiment conditions: the numerical outputs matched fairly well the experimental in-situ determinations. (C) 2015 Elsevier Ltd. All rights reserved.