DOUBLE-PULSE ONE-DIMENSIONAL RAMAN AND RAYLEIGH MEASUREMENTS FOR THE DETECTION OF TEMPORAL AND SPATIAL STRUCTURES IN A TURBULENT H-2-AIR DIFFUSION FLAME

A novel spectroscopic technique for the observation of the temporal de velopment of small spatial structures of temperature and major-species mole fractions in turbulent flames has been developed. It uses two in dependent lasers and linewise, single-pulse detection systems for Rama n-Rayleigh-scattered light. With this technique, all major-species con centrations, temperature, and positions of vortices and flame fronts, combined with scalar dissipation in two directions or heat release, ca n be measured, for the first time to our knowledge, as a result of one pair of laser pulses separated either in space or time. This yields, to our knowledge, the highest number of correlated quantities that hav e been obtained in probing turbulent flames of simple chemistry. (C) 1 996 Optical Society of America.