Study on the combustion limit, near-limit extinction boundary, and flame regimes of low-Lewis-number CH4/O2/CO2 counterflow flames under microgravity

To obtain an accurate and comprehensive understanding on the fuel-lean combustion limit, near-limit extinction boundary and flame regimes, experimental and numerical investigations using premixed counterflow flames were conducted for low-Lewis-number mixtures. Counterflow flame experiments were conducted under microgravity (2.2 ≦ a ≦ 12.9 s−1) and under normal gravity (35 ≦ a ≦ 150 s−1) using fuel-lean CH4/O2/CO2 mixtures (Le = 0.75) where a is...