Experiments of Formation and Combustion of Mono-dispersed and Mono-sized Spray in the Fifth TR-IA Rocket

Abstract

Experimental study on formation of a homogeneous spray and its ignition and combustion were carried out by using microgravity conditions produced by the fifth TR-IA rocket. Condensation method was applied to generate homogeneous sprays. Methanol and air were used as a fuel and ambient gas, respectively. Shadowgraphy, shearing interferometry and PIV were employed to observe behaviors of a flame and droplets. Experiments were performed three times in 6 minutes microgravity conditions. Since enough amount of fuel to make a saturated fuel vapor-air mixture was not charged into a combustion chamber, no spray was generated. However, it was observed that a flame kernel grew spherically up to about 14 mm diameter in very lean premixtures. Temporal variations of the temperature profile of a flame kernel were measured with the shearing interferometer. These detailed data on ignition of lean premixtures have never been obtained under normal gravity conditions.