Broken C-shaped extinction curve and near-limit flame behaviors of low Lewis number counterflow flames under microgravity

To examine the effect of Lewis number on the extinction boundary, flame regimes, and the formation of sporadic flames, microgravity experiments on counterflow flames for CH4/O2/Kr (Le ≈ 0.7–0.8) and CH4/O2/Xe (Le ≈ 0.5) mixtures, and three types of computations, which are one-dimensional computations with a PREMIX-based code using detailed chemistry, and three- and one-dimensional computations with the thermal-diffusion model using an overall...