  This study presents a systematic analysis of the capabilities of a flamelet
model based on Flamelet Generated Manifolds (FGM) to reproduce preferential
diffusion effects in partially premixed hydrogen flames. Detailed transport
effects are accounted for by including a mixture-averaged transport model when
building the flamelet database. This approach adds new terms to the transport
equations of the controlling variables in the form of diffusive fluxes where
the coefficients can be computed from the information contained in the manifold
and saved in the flamelet database. The manifold is constructed from the
solution of a set of premixed unstretched adiabatic one-dimensional flames with
mixture-averaged transport for a range of mixture fraction within the
flammability range. Special attention is given to the numerical aspects related
to the construction of the chemical manifold to reduce the numerical error in
evaluating the new terms derived from the preferential diffusion of certain
species. Finally, a systematic application of the method to simulate laminar
hydrogen flames in various canonical configurations is presented from premixed
to stratified flames, including the case of a triple flames with different
mixing lengths. The results demonstrate that the method describes accurately
the flame structure and propagation velocities at a low cost, showing a
remarkable agreement with the detailed chemistry solutions for flame structure
and propagation velocity.
