Fin-Guided Liquid Fuel Injection into Mach 2.1 Airflow

Abstract

An experimental investigation was performed to characterize liquid fuel injection into a Mach 2.1 airflow simulating a scramjet combustor flowfield. In particular, ethanol fuel penetration and dispersion characteristics were compared for a transverse injection configuration with and without a mixing enhancement fin. In previous studies involving gaseous fuel, the fin-guided injection not only improved turbulent mixing but also served to reduce the stagnation pressure loss associated with the fuel injection shock. To characterize the mixing between liquid fuel and air, laser-sheet visualization of the cross-sectional view and schlieren visualization of the side view were obtained at various time intervals. Wall pressure measurements along the axial direction were used to help interpret the visualization data. The side views of fuel injection revealed that the fuel penetration height in the near-field was two-to six-times greater with the fin-guided injection. Also, downstream evolution of the liquid-fuel cross-sectional area suggested a greater vaporization rate associated with the fin-guided injection. The present results showed a significant improvement in key injection parameters and mixing characteristics associated with fin-guided liquid-fuel injection.

Visualization of Vaporized Kerosene Combustion in a Supersonic Combustor Using Pulsed Schlieren System

“…Schlieren photography has been widely employed to visualize the processes of fuel injection, [1][2][3][4][5] fuel-air mixing, [6][7][8] fuel ignition, 9,10 flame holding, [11][12][13] shock/boundary interaction, [14][15][16][17] etc. However, few literatures could be found for the visualization of the combustion process in a scramjet combustor.…”