Atomic Recombination in Nozzles : Methods of Analysis for Flows with Complicated Chemistry
The object of this review is to study the feasibility of performing accurate calculations on the non-equilibzWm flow of a complicated gas mixture through nozzles, with partioular reference to the propulsive nozzle of the hypersonic ramjet. Equations are given for the steady, quasi-one-dimensional, adiabatic flow of a general reacting gas mixture, consisting of rl species related through N chemical reactions. A number of alternative methods of obtaining numerical solutions to these equations are described and evaluated. The formulation of the system of chemical reactions is also discussed, together with the availability of the large amount of thermodynamic and chemical kinetic data which is required before a numerical solution can be attempted. It is found that by far the most serious difficulti to be overcome, before accurate non-equilibrium nozzle calculations can be performed, is obtaining reliable data on the rates of the many chemical reactions which may be involved.
Aeronautical Research at the University of Southampton
F. W. Lanchester obtained his first technical education at the Hartley Institute in Southampton, later to become the University of Southampton, during the years 1886–89. His autobiography describes in vivid terms the primitive nature of the workshop and apparatus available. He would indeed be shocked at the wealth of modern equipment now encountered in engineering departments of a University. At the same time, no one can possibly say that this lack of equipment influenced his pioneer spirit or his extraordinary clarity of thought, not only in the fields of aeronautical and automobile engineering, but also in subjects as diverse as the musical scale, poetry and even relativity.
Reactions of Nitrogen Atoms. I. Oxygen and Oxides of Nitrogen
Several reactions of nitrogen atoms have been investigated in a low‐pressure flow system, using the principle of a ``stirred reactor'' and a mass spectrometer for the determination of steady‐state concentrations.The elementary processes which have been definitely demonstrated to occur and their rate constants are as follows: N+NO=N2+Ok1≥4×1011 cc mole−1sec−1(1)N=O2=NO+Ok8=2×1012×exp(−6200/RT) cc mole−1sec−1(8)N+NO2=N2O+O10−2k1<k9<10k1(10)O+NO=NO2k3≥1013 cc mole−1sec−1(3)O+NO2=O2+NOk6≥1012 cc mole−1sec−1.(6) Unless indicated, the rate constants are at room temperature.The rate constant of nitrogen atom reaction with nitrous oxide is less than 108 cc mole—1 sec—1 at 280°; that of oxygen atoms is less than 2×108 at room temperature, neither having been observed to occur.Nitrogen atoms probably react with nitrogen dioxide also by a different mechanism than (10), yielding 2NO and/or N2+O2, at a rate which is competitive with (10). Nitrous oxide is probably formed also by another mechanism, which does not invol...