Effects of ambient pressure and burner scaling on the flame geometry and structure of hydrogen jet flames in cross-flow

Abstract

The effects of ambient pressure and burner scaling on flame geometry and structure of a hydrogen jet flame in a cross-flow are presented. To delineate the effects of buoyancy, the fuel was injected horizontally into a vertically moving air stream, thus, buoyancy was aligned with the direction of the cross-flow. The combustion chamber pressure was varied from 1 to 1.45 bar, and the jet-to-cross-flow velocity ratio from 25 to 240. For flow visualization, Rainbow Schlieren Deflectometry (RSD) along with conventional flame photography was used. The centerline flame trajectory showed three distinct regions which were different from the previously reported findings where buoyancy acted along the jet axis. The dimensionless coordinate of the jet centerline in the jet direction varied with 0.5, 0.3, 0 power of the coordinate in the vertical cross-flow direction, and was correlated with 0.15 power of the burner diameter. The effect of pressure on flame trajectories was not significant. Flame chord length varied with −0.38 power of the jet-to-cross-flow velocity ratio.