Effects of interaction between chemical kinetics and fluid mechanics in a stagnation point boundary layer

Abstract

In the present study the mutual effects between thin-flame kinetics and fluid mechanics have been studied Tor a stagnation point flow with boundary layer approximations. The effects of fluid mechanics on the flame properties have been studied with three models (a) Blasius flow model (or Lees' approximation), (b) Falkner-Skan model and (c) 'Exact' model. II is shown that Blasius flow model overestimates the flame position by a large amount (much larger than 50% over most of the range). The Falkner-Skan model and 'Exact' model overestimate and underestimate, respectively, the flame position by roughly equal amounts (~20-30%). It is, however, shown by heuristic arguments that predictions of flame position will be more accurate provided actual Lewis number values (0.5-0.7) are used with the exact model. The fuel and product concentrations at the wall are under- and overestimated respectively by the Falkner-Skan model compared to the 'Exact' values. Finally, the velocity profile for a realistic case (with temperature profiles due to the experiments of Tsuji and Yamaoka) has been computed and presented.