Generation of PDFS for flame curvature and for flame stretch rate in premixed turbulent combustion

摘要: Abstract Experimentally derived pdfs of turbulent, premixed, flame curvatures from a variety sources, for wide range conditions are surveyed and suitable expression sought to generalize these. This proves be one based on the Damkohler number, Da. is tantamount normalizing curvature by multiplying it Taylor scale turbulence. It enables distribution when normalized laminar thickness, expressed in terms Karlovitz stretch factor, K, turbulent Reynolds R l . The value pdf at zero linearly related Da 1/2 expressions Yeung et al. [3] obtained numerical simulations used strain rate and, assumption that these statistically independent, values generated numerically. necessary define an appropriate surface burning velocity, rate, Markstein numbers. Two surfaces considered employed computations, located start preheat zone, other reaction zone. latter seems more rational gives better generalisation rate. An assumed linearity velocity with extending over both positive negative rates, generated. concluded unlikely velocities should tend rather than attain values. modifies derivation pdfs. These depend factor number. Computations suggest that, K above 0.1 100, similar At very low pronounced flamelet instability might anticipated.