Flame acceleration in stoichiometric H 2/O 2 at 12 and 25 kPa initial pressure in an obstacle-
laden square cross-section channel was studied experimentally using planar laser-induced
fluorescence imaging of hydroxyl radicals (OH-PLIF) and simultaneous high-speed
schlieren imaging. Results were obtained resolving the explosion front structure as it
develops immediately after ignition as a slow-flame to the eventual formation of a shock-
flame complex in the fast-flame regime. The images provide a novel level of detail and allow …

Flame propagation across a single obstacle in a closed channel has been studied by means
of simultaneous singleimage OH-PLIF and high-speed schlieren visualization. The test
mixtures are stoichiometric H2/O2 at an initial pressure of 8 kPa and lean H2/air (Φ= 0.5) at
an initial pressure of 100 kPa. The OH-PLIF technique overcomes the problem of line-of-
sight integration associated with schlieren visualization and thus enables the investigation of
flame topology. For H2/O2, a smooth (laminar) flame front is observed upstream of the …