Flamelet modeling of thermo-diffusively unstable hydrogen-air flames

In order to reduce CO2 emissions, hydrogen combustion has become increasingly relevant for technical applications. this context, lean H2-air flames show promising features but, among other characteristics, they tend exhibit thermo-diffusive instabilities. The formation of cellular structures associated with these instabilities leads an increased flame surface area which further promotes the propagation speed, important reference quantity design, control, and safe operation combustors. While many studies have addressed physical phenomena intrinsic in past, there is also a demand predict such characteristics reduced-order models allow computationally efficient simulations. work, spherical expanding flame, exhibits instabilities, studied flamelet-based modeling approaches both a-priori a-posteriori manner. A recently proposed Flamelet/Progress Variable (FPV) model, manifold based on unstretched planar flames, novel FPV approach, takes into account large curvature variation tabulated manifold, are compared detailed chemistry (DC) calculations. First, assessed terms test DC dataset. Thereafter, assessment contains two parts: linear stability analysis perturbed simulation flame. Both systematically analyzed considering global local properties comparison data. It shown that new incorporating variations improved predictions microstructure corrugated front structures, while reasonably well reproduced by models.