Nitrogen Catalytic Recombination on Copper Oxide in Tertiary Gas Mixtures

Abstract

Catalytic phenomenon of copper oxide in a test gas consisting of a mixture of 35% nitrogen and 65% krypton has been investigated experimentally. The heat-transfer rates at the stagnation point of a blunt body are measured in a shock tube using a thin-film gauge. In the experiments, two flow conditions are considered that produce nitrogen dissociation. The surface of the test model was coated with silicon dioxide, copper oxide, or copper. The heat-transfer rate of a copper-oxide-coated model was approximately 7 to 11% higher than that of a silicon-dioxide-coated model. The heat transfer on the copper model was approximately 22% higher than that to the silicon-dioxide-coated model. Nitrogen catalytic recombination efficiency is obtained by analyzing the measured heat-transfer rates along with the existing theories based on binary and tertiary gas mixtures. The efficiency of copper oxide is deduced to be 0.00061 to 0.0014 at a partial pressure of atomic nitrogen of 21 to 30kPa, whereas copper has an efficiency of 0.053 at 30kPa. The wall temperature increased from approximately 290 to 340K throughout the experiments.