An Overview of a Micro-Scale Gas Turbine Combustor Test Campaign

Miniature gas turbine engines have drawn considerable attention over the past two decades as lightweight, attritable propulsion and power systems for unmanned defense applications. However, size constraints and severe metrics for lightability and performance have forced engine manufacturers to explore novel component technologies and combustor designs under rapid iterative testing to meet the desired mission requirements. Southwest Research Institute has developed a small-scale gas turbine engine combustor test facility to support the high volume of tests required by these engine manufacturers. The facility is capable of flowing up to 2 lbm/s of airflow at 500 °F in order to simulate the compressor outlet temperatures associated with relevant flight conditions. In collaboration with Acutronic Turbines, Inc., combustor development testing has been performed across a wide range of operating conditions to characterize ignitability and operational mapping of various combustor designs. Raw and post-processed data for various combustor designs was gathered including exhaust temperature, pressure loss, combustor efficiency, and operational flammability limits. Various experimental phenomena, such as pattern factor shifts, rich/lean blow off, and instability-driven flame extinction were observed and are discussed herein. Future work includes continued atmospheric sea-level testing alongside the development of an altitude test facility capable of simulating up to 36,000 ft for full-scale micro-GT engine testing.