In combustion, heat release parameter (or gas expansion parameter) is a dimensionless parameter which measures the amount of heat released by an adiabatic combustion process.Williams, Forman A. "Combustion theory." (1985).Linan, Amable, and Forman Arthur Williams. "Fundamental aspects of combustion." (1993). It is defined as
where is the adiabatic flame temperature is the unburnt mixture temperature.
In typical combustion process, . For isobaric combustion, using ideal gas law, the parameter can be expressed in terms of density,Clavin, P. (1985). Dynamic behavior of premixed flame fronts in laminar and turbulent flows. Progress in energy and combustion science, 11(1), 1-59. i.e.,
The ratio of burnt gas to unburnt gas temperature is
Gas expansion ratio
The gas expansion ratio is simply defined by
which is related to by
See also
Zel'dovich number
References