Perturbations of the flame structure due to a thermocouple. II. Modeling

Flame perturbations caused by the presence of a thermocouple have been studied by modeling the external flow of a reactive gas mixture around a thermocouple using the complete system of unsteady Navier-Stokes equations modified to approximately account for the effect of heat release due to chemical reactions. The modeling was performed for a methane gas flame and for the flame of a condensed system exemplified by RDX under the experimental conditions described in the literature. It is found that the deceleration of the flow in the vicinity of the thermocouple leads to a local increase of heat due to chemical reactions and the corresponding increase in temperature relative to the thermocouple unperturbed value. This effect has not been previously discussed in the literature.