PDF modeling of a bluff-body stabilized turbulent flame

Abstract

The velocity-turbulent frequency-compositions PDF method combined with the consistent hybrid finite volume (FV)/particle solution algorithm is applied to a bluff-body stabilized turbulent flame. The statistical stationarity is shown and the performance of the PDF method is assessed by comparing the mean fields with the available experimental data. The effects of the model constants C-omega1 in the turbulence frequency model and C-phi, in the mixing model on the numerical solutions are examined and it is found that all the mean fields are very sensitive to the changes in C-omega1 while only the mixture fraction variance seems to be very sensitive to the changes in C-phi but not the other mean fields. The spatial and bias errors are also examined and it is shown that the hybrid method is second order accurate in space and the bias error is vanishingly small in all the mean fields. The grid size and the number of particles per cell are determined for a 5% error tolerance. The chemistry is described by the simplest possible flamelet/PDF model. Hence the main focus of the paper is on the accurate calculations of the mean flow, turbulence and mixing, which lays the foundation for future work in which the chemistry is described in greater detail.