Comparison of electron and electronic temperatures in recombining nozzle flow of ionized nitrogen—hydrogen mixture. Part 1. Theory

Abstract

This is part 1 of a two-part paper. In this part, relaxation of the population distribution of electronic states is studied theoretically for a highly-ionized nitrogen- hydrogen mixture expanding through a nozzle, wherein the hydrogen content is less than 0.1 %. The analysis incorporates quantum-mechanical excitation rate coefficients, and considers the effects of wall cooling and absorption of radiation. Calculations are carried out for a condition produced experimentally, the experiment being the subject of part 2. The electronic excitation temperatures are deduced from the computed population distributions along the nozzle, and are compared with the calculated electron temperatures; this shows a large discrepancy between the two.