CHEMICAL KINETICS AND FLUID DYNAMICS OF SURFACE-CATALYZED ATOME AND FREE-RADICAL REACTIONS.

The research reviewed in this report concerns the kinematics and kinetics of reacting gases of interest in advanced propulsion systems. The experimental measurements have included (1) the dynamics of interaction between atoms and solid surfaces, (2 0 the kinetics of gas-phase reactions involving atomic species (including chemionization), and (3) the transport parameters of high-temperature reacting gas mixtures containing atoms. New techniques have been developed to carry out the experimental measurements with chemical species of high reactivity and short lifetimes. The results have shown quantitatively the nonequilibrium behavior of exothermic gas-solid reactions, the role of energy transfer during homogeneous and heterogeneous collisions, and the magnitude of the interaction parameters applicable to high-temperature gas mixtures containing dissociated species. Some applications of these results to problems of propulsion and high-velocity flight are briefly explored in this report. These include (1) enhancement of specific impulse in hypersonic propulsion systems: (2) evaluation of the drag coefficient of a body in motion in rarefied atomic gases; (3) detection of atoms in high-velocity gas streams; and (4) analysis of boundary layers associated with chemical reaction.
Prepared in cooperation with Stanford Research Inst., Menlo Park, Calif.