ESTIMATES OF OXIDES OF NITROGEN FORMED IN A SCRAMJET INLET

Estimates of oxides of nitrogen formed in the inlet air stream were made for the forebody and internal sections of a generic inlet operating at high-speed flight conditions. Computational fluid dynamics analyses were used to compute typical inlet flow fields. Oxides of nitrogen levels were calculated using these flow fields together with a reaction rate mechanism as input to a chemical kinetics code. It was found that negligible amounts of these species are produced everywhere but in a small region of the air flow captured by the inlet and located near its surfaces. The static temperature reduction associated with oxides of nitrogen formation in the inlet is also insignificant except near inlet surfaces.