Interaction between Two-Dimensional Sonic Jets and Supersonic Flow to Model Heat Addition in a Supersonic Combustor

摘要

Displacement effects of heated addition to a supersonic flow through a simulated combustor were simulated with mass addition. The structure of precombustion shocks was experimentally investigated by an optical and pressure study of two parallel sonic jets expanding into a two-dimensional supersonic test cavity. Base flow and recompression shocks were studied for two test section depths. A test section to add heat to a two dimensional flow was demonstrated. It was determined that the performance of the constant-area test section was dominated by frictional, rather than shock effects. An off-design nozzle, used for preliminary investigation, caused turbulence and high losses in the channel. The structure of the precombustion zone was found to be a base flow problem and was analyzed using a simple one dimensional model. Static pressure measurements on the sidewalls of the test cavity were found to differ from the static pressure in the center of the two dimensional test cavity, due to diffusion of pressure upstream and downstream through the boundary layer. A welding torch was used to inject premixed oxygen and acetylene into the base region on the end of a centerbody between two supersonic nozzles. The flame was successfully ignited and burned continuously in the flowstream. However, the large amount of heat added caused flow separation in the supersonic nozzles.