Study on the influence of the combustion chamber baffle on atomization characteristics of gas-centered swirl coaxial injector

The combustion chamber baffle is an important means to suppress the combustion instability of the combustion chamber of liquid rocket engine. In order to study the influence of spray impacting on the baffle on the atomization characteristics of injector, sufficient experimental research has been carried out in this paper. In the present study, the effects of different gas/liquid flow rates and different baffle structures on the atomization characteristics are investigated. The results show that for gas-centered swirl coaxial injector, a wall film is formed on the baffle when the spray impinges on the baffle and it is broken into liquid ligaments and droplets downstream of the baffle by centrifugal force, resulting in a slower spray velocity near the baffle, a significantly larger sauter mean diameter, an increase in flow flux downstream of the baffle and worse spray uniformity. In addition, it is found that there is a spray zoning phenomena by comparing the spray with different baffles.