Excerpt of the FLUT obtained from unsteady flamelet solutions (dots, colored by their respective Y_C value) under stoichiometric conditions. The boundary conditions are given in Table 1. Solid black lines are built by stable steady flamelet solutions and the dashed black line denotes unstable steady solutions. Black arrows indicate the direction of evolution of the unsteady solutions depending on their initial condition. The value of χ_st until which high-temperature ignition is possible is marked by a vertical gray dashed line and denoted by χ_st,ign. Possible T − χ_st trajectories for the original UFPV approach are indicated by a red solid line while the corresponding trajectory for the RUFPV approach following equation (25) is shown by a blue dashed arrow.