EXPERIMENTAL INVESTIGATIONS OF DROP SIZE DISTRIBUTIONS WITH IMPINGING LIQUID JETS USING PHASE DOPPLER ANEMOMETER

A parametrical study of drop size distribution has been conducted using a phase Doppler anemometer. A liquid spray is generated by two impinging nozzles at the same pressure, and the experiments have been performed under ambient pressure conditions (1 bar). For a 0.51 mm diameter, the range of free liquid jets Reynolds and Weber numbers investigated is rather large and higher than most studies: namely, 12,000 < Re < 40,000, and 4000 < We < 40,000. The Sauter mean diameter is compared at different locations mainly along the centerline and for different impingement angles. The purpose of these inert conditions tests is to have at first approach reference data to gain insight into reactive conditions. Experiments are performed with water or ethyl alcohol (fuel), whereas 87.5 wt % hydrogen peroxide tests remain to be done (oxidizer). These two liquids are studied for the purpose of a possible substitution to present-day propellants used in liquid propulsion rocket systems, many of which are considered as very toxic for the environment and hard to handle. With a like-onlike doublets configuration, the choice of operating conditions such as pressurization and injection geometry giving access to a specific mixture ratio determines an estimation of fuel and oxidizer evaporation times. Similar values of fuel and oxidizer evaporation times are targeted because this would result in favorable conditions toward ignition and combustion.