Liquid Motor Combustion Stability Using Coaxial Injectors

摘要

The Final Report documents the first fifteen months of work on an experimentalinvestigation of the sources of combustion instability in liquid propellant rocket motors using coaxial injectors. Three possible contributions to combustion instability are being investigated: atomization characteristics, flameholding by means of a recirculation region at the base of the LOX post and gas side injector coupling. The atomization is characterized by means of a Phase Doppler Particle Analyzer (PDPA). Initial results are presented for a full size SSME preburner injector operating with water and air at atmospheric pressure. Future experiments are planned using either liquid nitrogen or liquid oxygen with either nitrogen or helium as the simulant gas at chamber pressures up to 10 MPa. In order to simulate the hydrogen temperature ramping test, a liquid nitrogen heat exchanger to cool the simulant gas has been designed and is under construction. An LDV system has been assembled to probe the region at the base of the LOX post to determine if a recirculation region exists there and if so to measure its strength. Combustion instability, Liquid rocket motors, Coaxial injectors, Phase Doppler Particle Analyzer.