Abstract:
Suitable forms of the equations for the flow of an inviscid, non-heat-
conducting gas in which chemical reactions are occurring are derived,
The effects of mass diffusion and non-equilibrium amongst the internal
modes of the molecules are neglected.
Special attention is given to the speeds of sound in such a gas
mixture and a general expression for the ratio of frozen to equilibrium
sound speeds is deduced. An example is given for the ideal dissociating
gas. The significance of the velocity defined by the ratio of the convective
derivatives of pressure and density is explained. It is the velocity
which exists at the throat of a convergent-divergent duct under maximum
mass flow conditions, and it is shown that this velocity depends on the
nozzle geometry as well as on the 'reservoir' conditions.
As an illustration the phenomena of sound absorption and dispersion are
discussed for the ideal dissociating gas. The results can be concisely
expressed in terms of the frozen and equilibrium sound speeds, the
frequency of the (harmonic) sound vibration and a characteristic time for
the rate of progress of the reaction.
