HyperMATE: A Novel Aerothermal Testing Facility at the University of Tennessee

The design and implementation of new thermal protection systems for hypersonic flight requires extensive knowledge of how the high-temperature, chemically reacting flow interacts with the material surface. Analysis of these gas–surface interactions is commonly performed in high-enthalpy ground testing facilities, however the demand and cost of large-scale plasma wind tunnels reduces their viability for supporting the material development process. To this end, the University of Tennessee has constructed a continuous 60-kW plasma torch facility known as Hypersonic MAterial TEsting (HyperMATE). This torch utilizes three commercial plasma cutters as plasma sources that discharge to a common copper anode. The plumes mix in a plenum chamber past the anode and evacuate from a converging nozzle, producing a subsonic flow that mimics the stagnation point heating conditions encountered in hypersonic flight. This paper focuses on the design and characterization of this facility, describing the electric arc generation process and detailing the experimental techniques used for characterizing the flow temperature, pressure, and heat flux. A testing campaign on graphite disks will be discussed, displaying the capabilities of the facility and the optical instrumentation used to measure in situ surface temperature and emissivity.