COMPUTATIONAL INVESTIGATION OF SHOCK-ENHANCED MIXING AND COMBUSTION

A computational investigation of shock-enhanced mixing and combustion is presented. To understand the influences of the mixing process on th e combustion process, the mixing characteristics of the reacting case are compared with those of the nonreacting case. Parametric studies va rying the conditions of fuel injection are conducted to find the trend s of the mixing and combustion processes. Three-dimensional Navier-Sto kes equations with a chemical reaction model and k-omega turbulence mo del are used. The upwind method of Poe's Bur difference splitting sche me is adopted. It is shown that the mixing process has a strong influe nce on the combustion process, whereas the combustion process does not have any significant effect on the mixing process. The combustion pro cess is divided into two mixing regimes: a convection-dominated regime , where the burning rate increases with distance from the injection pl ane, and a diffusion dominated regime as one moves downstream, where b urning rate is constant. In the parametric studies, varying the fuel p ressure with the fuel density held fixed makes little difference, wher eas varying the fuel density makes a significant difference in mixing rate and burning rate. A prediction of minimum combustor length for co mplete combustion is made.