Concentration imaging measurements in turbulent concentric-jet flows
Raman scattering images were used to determine the CH 4 concentration in nonreacting concentric-jet flows. The flow consists of a central CH 4 jet and a concentric air jet separated by a bluff body. Three jet velocity ratios were studied under isothermal conditions. At high momentum-flux ratios, the CH 4 jet penetrates the recirculation zone formed by the airflow behind the bluff body. At low momentum ratios, the jet is stagnated and fuel is dispersed into the recirculation zone