The characteristics of partially-premixed flames is investigated by
simulating a series of triple flames with different variations of chemical
equivalent ratio. A two-dimensional Reaction-Diffusion Manifold (REDIM)
chemistry tabulation method is employed in the simulation and the results
are compared with the methane-air 19-step chemical reaction mechanism. The
performance of these two mechanisms is then assessed by using direct
numerical simulations coupled with GRI3.0 detailed mechanism. It is shown
that both 2D REDIM table and 19-step simplified mechanism can describe the
temperature and main products accurately, however, for some minor
intermediary products, predictions from 2D REDIM table is observed to be
better than 19-step simplified mechanism. Compared with the 19-step
mechanism, 2D REDIM table only needs to solve only the transport equations
for CO2 and N2 species, which greatly simplifies the solution process of
chemical reaction and provides a reliable solution for the numerical
simulation of turbulence with higher accuracy. This work indicates that as a
relatively advanced kinetic simplified method, the REDIM tabulation method
can reduce the computational cost and at the same time retain the accuracy
effectively.