Development and characterization of a small-scale optically accessible solid-fuel ramjet direct-connect facility
Ryan DeBoskey, Abinash Sahoo, Muhammad Khan, Simon Gneuss, M. Fischer, Venkateswaran Narayanaswamy
Abstract
The present work details the development and characterization of a novel small-scale optically accessible solid fuel ramjet (SFRJ) direct-connect facility. This modular facility is designed to deliver high-pressure high-enthalpy air to simulate a range of relevant flight conditions for hypersonic platforms powered by ramjet propulsion. The SFRJ test section is designed for computational tractability, whilst providing a large enough size to be relevant to small engine design. Uncertainty of various operational quantities are calculated using the Monte Carlo method. Particle-image velocimetry and thermal profiling are conducted at the test section inflow to characterize the incoming velocity and thermal profiles. High-speed flame imaging is performed for both flame luminosity and CH* chemiluminescence to capture instantaneous and time-averaged combustion dynamics. Spent fuel grains are processed using a photogrammetry technique to capture the two-dimensional surface regression rate. The results suggest a large amount of soot buildup within the recirculation zone, with the bulk of heat release within the recirculation shear layer. Surface regression rates show excellent repeatability between runs, with wall-quenching effects and recirculation char deposits captured.