Affiliations: Department of Mechanical Engineering, Stanford
University, Stanford, California 94305, U.S.A.
Abstract: We present simultaneous planar velocity and OH fluorescence
measurements at the base of a lifted, nonpremixed, transverse methane jet flame
of Reynolds number 6300 and jet-to-crossflow velocity ratio 11.5. Velocity
measurements are obtained using particle image velocimetry (PIV), while
nonresonant OH fluorescence is imaged via excitation of the A ← X
(1,0) band near 283 nm. It is shown that at the flame base, the regions in the
PIV images where particle density drops due to heat release closely overlap the
regions where OH appears. Other preliminary results show that the base of the
flame sheet typically resides just above a region where velocity magnitude is
locally low, about three times the laminar flame speed, and that the fluid
accelerates suddenly through the flame base. Experimental issues such as PIV
accuracy and OH imaging in the presence of PIV particles are discussed.