This paper summarizes the development and flow characterization of the Osney Plasma Generator thermal arcjet facility at the University of Oxford. The small-scale facility is the first of its kind in the United Kingdom, capable of testing material responses under high-enthalpy flows and serving as a model preheating device for impulse facilities. The new plasma generator produces steady argon, nitrogen, and air plasma jets, utilizing currents up to 500 A DC and gas mass flow rates of up to 0.2 g/s. Measurements from hemispherical slug calorimeters and total pressure probes indicate a maximum stagnation point heat flux of 5.24 MW/m 2 and freestream stagnation pressure of 7.85 kPa, which corresponds to a mass-specific stagnation enthalpy of 19.67 MJ/kg. A fiber-coupled spectrometer was used to examine the species composition of the plasma from the broadband radiation between 300 nm and 1200 nm. The data showcased that the present facility could generate comparable heat fluxes to large-scale facilities at higher equivalent altitudes. A ground-to-flight extrapolation was performed using full plasma flow scaling, showcasing a range of conditions with flight-equivalent velocities of up to 6.23 km/s at altitudes of 51–67 km. The scaling also provided an initial comparison of the effective nose radii between the sub-scale model and the full-scale vehicle. • Development and characterization of a small-scale thermal arcjet facility. • Generation of steady plasma flows using argon, nitrogen, and air composition. • Stagnation-point heat fluxes comparable to those in large-scale arcjet facilities. • Compact, cost-effective platform for high-temperature material testing. • Ground-to-flight extrapolation reveals scaling of probe geometry to nose radius.
Chang et al. (Sun,) studied this question.