Spontaneous Ignition of Methane–Air Mixtures in a Wide Range of Pressures

Abstract

The ignition delay in methane–air mixtures ϕ = 0.5) within the range of temperatures of 1200–1700 K and pressures of 3–450 atm behind reflected shock waves in a shock tube is measured on the basis of emission of the electron‐excited OH radical (transition A2Σ+ – X2Π) at the wavelength of 306.4 nm and on the basis of absorption corresponding to the component F1 (2) (ν3 = 1) ← F2 (2) (ν3 = 0) of the P(7) line of the ν3 mode of the CH4 molecule at the wavelength of 3.3922 μm. The measured ignition delays are compared with those calculated by the GRI‐Mech 3.0 mechanism; good qualitative agreement of results is obtained in a wide range of pressures.