Heat Transfer from Argon and Xenon to the End Wall of a Shock Tube

Abstract

Heat transfer from argon and xenon to the end wall of a shock tube has been measured by using a thin‐film heat transfer gauge whose temperature rise is monitored by an infrared photocell. Experiments were carried out at initial pressures between 1 and 10 mm Hg in argon and between 0.75 and 2 mm Hg in xenon. For the range of incident shock Mach numbers tested, between 9 and 13 in argon and 13 and 18 in xenon, partial ionization would exist behind the reflected shock wave if thermodynamic equilibrium were achieved. By extrapolation of measured ionization rates for these gases, it was concluded that no ionization occurred behind the reflected shock wave in argon but that equilibrium was achieved in xenon, at least for the period during which the heat transfer was measured. Calculations of the heat transfer, made in accordance with existing theories for the corresponding thermodynamic state of the gas, were found to be in good agreement with the experimental measurements.