Set up of an experimental protocol for the investigation of graphite combustion in supersonic flow

• Combustion of graphite rods occurs in supersonic conditions at 1200 °C < T < 2200 °C.
• A Planetary Entry Simulator with a plasma torch is used to investigate graphite combustion.
• Measured rates of carbon consumption follow Miller and Sutton’s equation.
• Above 1900 °C K combustion stoichiometry changes from C + O2 → CO2–C + 1/2O2 → CO.

The paper reports on the set up of an experimental protocol for the investigation of high temperature (1200 °C < T < 2200 °C) graphite combustion in supersonic flow conditions. Cylindrical graphite specimens (3 mm D, 100 mm L) are exposed to supersonic flow of nitrogen/oxygen mixtures in a small Planetary Entry Simulator, equipped with a plasma torch. The impact of the gas flow on the specimen determines a very sharp temperature rise. A fast IR camera allows to realize two-dimensional maps of the specimen temperature throughout the experiment. IR thermal images can also be of help to rebuild the consumption of the graphite rod. Results are checked against the sample weight loss and used to estimate the rate of carbon combustion as a function of temperature and reaction time.