Effects of the Initial Heat-Up Period on a Two-Droplet Array Burning at High Pressure in Microgravity

摘要

The interactive combustion of two closely--spaced droplets at elevated pressures was investigat- ed experimentally in a 2.2 second drop tower. Heptane, hexadecane and mixtures of the two were the fuel, and a nitrogen--oxygen ambient with a relatively low oxygen concentration was employed to facilitate observaton of droplets during combustion at elevated pressures. Results show that staged combustion of binary fuel droplets still exists for interacting droplets at elevated pressures. For pure fuels, it is shown that the interaction effects are principally observed during the initial heating period. For fuel mixtures, interaction effects are estimated by comparing transition time of single droplet and that of two droplets.