CHARACTERIZATION OF THE NEAR-INJECTOR REGION OF COAXIAL JETS

The objective of this study is to investigate the atomization of a water jet by a coaxial air jet, in the near field region. Experimental flow velocities and injector geometry try to simulate the conditions present in a VULCAIN engine. By means of laser light sheet, fiber optic as phase sensor for the dense phase and PDPA for the spray, the main following results were obtained: i) the length to hole diameter ratio highly influenced radial and axial Liquid Presence Probability distributions (LPP=1 - void fraction) while the Sauter Mean Diameter in the dilute spray seemed less influenced, ii) the recess of the liquid injector both significantly affected LPP and D₃₂ distributions. This was also observed with laser tomography.