Investigation of Combustion and Altitude-Ignition Performance of a Small Hydrogen-Fueled Reversed-Flow Turbine Combustor

This paper describes altitude ignition experiment results for a scaled hydrogen-fueled turbojet engine model applied for Balloon-Based Operational Vehicle in-flight testing. Although hydrogen has remarkable combustion characteristics among the combustion fuels, at low pressures, the hydrogen-fueled combustor showed difficulty in the originally planned altitude ignition conditions. The follow-up step-by-step refinement of the ignition sequence is explained using experimental data. A similar situation might occur for future hydrogenfueled High Altitude Long Endurance (HALE) flights. These limited but still wide combustion capabilities of the hydrogen fuel might facilitate the introduction of gas-turbine power plants in the HALE flights.