Influence of Row Dispersers on 3O-mm Gun-Type Annular Jets -- XM46 Combustion andFlash X-ray Photography of Aqueous NaI Solutions

摘要

This report summarizes an experimental study to characterize the influence of theinjector exit configuration on the flow and combustion dynamics of regeneratively injected XM46. In particular, it identifies differences in the spray structure and combustion dynamics produced when a 600 wedge flow disperser is attached to a basic injector configuration. The study consisted of two parts. The first part involved characterizing the structure of aqueous sodium iodine (NaI) sprays via flash x ray and scattered visible light photography. NaI solutions were injected at velocities rangmg from 25 to 76 mis into nitrogen at 7.6 or 17.2 MPa. It was found that in tests where the flow disperser was not used, the sprays tended to collapse and concentrate along the chamber centerline. When the flow disperser was employed, the liquid scattered away from the center, and a more uniform distribution of the liquid was produced in the chamber. In the second part of this study, XM46 sprays were ignited in the combustion products of O2/H2/Ar gas mixtures. The intial chamber pressure was 9-10 MPa, and the XM46 combustion elevated chamber pressures into the range of 30-45 MPa. Pressure oscillations developed at peak combustion pressures when the basic injector configuration was employed, but not when the flow disperser was attached. These results, coupled with the results from the flash x-ray experiments, suggest that the pressure oscillations are attributable to the spontaneous ignition of poorly dispersed blobs of XM46. (AN).