: A method of solution of the laminar boundary layer equations for dissociating and ionizing air in chemical nonequilibrium is formulated for arbitrary pressure gradients and body geometry A nonsimilar, multistrip integral technique is employed in conjunction with previously derived transport and thermodynamic properties for the multicomponent mixture Several numerical examples are carried out for sharp conical bodies (assuming a fully catalytic cold wall) at reentry velocities and altitudes between 115 and 200 kilofeet The results are used to demonstrate a number of salient features of the flow fields; among these are the dominant role of diffusion in counterbalancing the production of dissociated and ionized species, the relative importance of accurate transport properties in the momentum and energy equations (as reflected in the species production), and the persistence of chemical nonequilibrium to relatively low altitudes (below 15 kilofeet) for slender, sharp vehicles at reentry velocities (Author)

Nonequilibrium, nonsimilar solutions of the laminar boundary layer equations (task 3.1. flow-field analyses. rest project),

A computational study has been performed to explore the effects of finite catalytic walls on hypersonic flows. Boundary conditions for noncatalytic, fully catalytic, and finite catalytic walls have been incorporated into an upwind parabolized Navier-Stokes code. Nonequilibrium laminar airflows over sharp cones at 0 and 10 deg angle of attack were computed and the results are compared with previous results wherever possible. A study of finite catalytic cases was performed using varying recombination rates. Full ranges of catalycities were explored in the context of the surface energy balance as well as a constant wall temperature assumption. Detailed effects on specie concentrations, temperature, and heat transfer are presented.

Computation of hypersonic flows with finite catalytic walls

A mathematical model of laminar axisymmetrical natural gas flames

Computation of hypersonic flows with finite-catalytic walls

Chemical processes are central to the comprehension of rocket and missile exhaust structure. Afterburning of superstoichiometric, reduced products drives heating beyond the nozzle. Trace metals can suppress radical cycling intensities and simultaneously act as the source of ionization. Particles inorganic and otherwise undergo fluid slip and thereby impact heat and momentum budgets. All radiation interactions of the plume are intimately coupled into this rich chemical environment. Several atomic and chemiluminescent spectra appear in the submicron range. A variety of particulate types glow as continuum blackbodies in the infrared. Subject to quantum mechanical restrictions, major and trace gases emit as well. Radio frequencies are attenuated by the weak plasma and may also be generated where charge separation and turbulence conjoin. Renewed interest in missile defense will motivate refinements in plume detection, particularly for the boost phase. We review current theory and modeling of exhaust chemistry ...

Adeleke O. Oyegbesan

Papers

Numerical analysis of a non-equilibrium turbulent free jet diffusion flame

Non-equilibrium laminar boundary-layer flow of dissociating air