Assessment of the Flamelet Generated Manifold method with preferential diffusion modeling for partially premixed hydrogen flames

As a result of work carried out within HYINHEAT, we are pleased to share the peer-reviewed publication “Assessment of the Flamelet Generated Manifold method with preferential diffusion modeling for partially premixed hydrogen flames”, published in the journal Combustion and Flame.

Abstract

Accurate numerical modelling of hydrogen combustion is essential for the development and optimisation of hydrogen-based heating technologies. However, the high diffusivity of hydrogen introduces preferential diffusion effects that can make the simulation of hydrogen flames particularly challenging.

This study presents a systematic assessment of a flamelet model based on Flamelet Generated Manifolds (FGM) to reproduce preferential diffusion effects in partially premixed hydrogen flames. Detailed transport effects are incorporated through a mixture-averaged transport model when constructing the flamelet database, introducing additional terms into the diffusive fluxes of the controlling variables. Particular attention is given to the numerical construction of the chemical manifold and to reducing numerical errors when evaluating gradients in composition space.

The methodology is applied to several canonical configurations of laminar hydrogen flames, ranging from premixed to stratified flames and including a triple flame with different mixing lengths. The results show that the proposed FGM approach can accurately reproduce flame structure and propagation velocities while maintaining a low computational cost, achieving strong agreement with detailed chemistry solutions.