Transverse jets and jet flames. Part 2. Velocity and OH field imaging

Detailed measurements of the velocity field in the symmetry plane of two je ts and two jet flames in a crossflow are obtained using particle image velo cimetry. The jets issue into a wind tunnel at density-weighted jet-to-cross flow velocity ratios r = 10 and r = 21, with corresponding Reynolds numbers 6000 and 12 800. Ensemble statistics of the velocity field are presented, and some interesting features of the entrainment process in transverse jets are discussed. Deviations from the simple behaviour predicted by the simil arity analysis presented in Part I are highlighted. Simultaneous planar las er-induced fluorescence imaging of the OH radical is performed in selected regions of the flames. Results suggests that flame/flow interaction is stro ng near the lifted flamebase, but increasingly weaker further downstream.