“…The relative error (%) in the delay time upper bound versus the initial radius of droplets and Relative error (%) in the delay time upper bound versus the number of dropelts per unit volume are presented in Figure . The next model that have been presented by the authors of (Babushok & Goldshtein, 1988;Gol'dshtein & Sobolev, 1992;Goldfarb et al, 1997;Goldfarb, Gol'dshtein, Kuzmenko, & Greenberg, 1998;McIntosh, Gol'dshtein, Goldfarb, & Zinoviev, 1998;Goldfarb, Gol'dshtein, Greenberg, & Kuzmenko, 2000;Sazhin et al, 2001; ) generalized the model of in such way that the model take into account the effect of thermal radiation of heat transfer between the droplet and gas in different way and more precisely. The main physical assumption of the model are: The contribution of the thermal radiation based on the P − 1 approximation for the thermal radiation transfer with Marshak boundary condition (Modest, 1993;Sazhin et al, 1996;Siegel & Howell, 2002;), the spray is monodisperse spray, the droplets are opaque, their surface are gray, and the radiative temperature T r is equal to the gas temperature T g , the Spalding number is small, the characteristic time of droplet t d and gas t g for typical diesel engine parameters satisfies the inequality t d << t g and the droplet heating can be neglected.…”