Modelling of turbulent gas/particle combustion by a Lagrangian PDF method

A mathematical model for two-phase turbulent reactive flows is presented wh ich is based on considering both phases in Lagrangian manner. The mechanica l and thermodynamical properties of the two-phase mixture are calculated al ong the trajectories of "particles" representing the system. Similar to Mon te-Carlo methods for solving a high dimensional joint velocity-composition probability density function, the turbulent gas phase is described by means of stochastic calculus. The deterministic equations for individual solid p articles can be treated directly. In this approach, the interaction between both phases is not smeared over computational cells but restricted to the vicinity of solid particles by the definition of an "action-sphere" which i s attached to every solid particle. Applications of the method to isotropic , homogeneous turbulence indicate that it is capable of providing informati on on the local structure of combustion zones with species formation and tr ansport. The results show that the method is applicable independent of the combustion modes in the gas phase and it provides extensive statistics of v arious correlations of properties.