Boom Starts Supersonic Engine Combustor Rig Tests

Boom Supersonic has begun rig tests of the combustor section at the heart of the 35,000 lb.-thrust Symphony turbofan in development to power the Colorado-based company’s Mach 1.7 Overture airliner.

Disclosing the first significant new details of the engine testing since Boom announced it would develop its own propulsion system in late 2022, the company says it will conduct more than 30 rig tests in collaboration with its design partner Florida Turbine Technologies (FTT), a business unit of Kratos.

Tests are being conducted at FTT’s design and test facility in Jupiter, Florida, using an additively manufactured one-eighth section of the combustor module. The 4 ft.-long full test section incorporates a compressor diffuser, combustion chamber, fuel nozzles, and secondary air system passages. The unit includes nearly 80 static and total pressure ports.

Boom says initial combustor rig testing forms the first phase of a two-phase pressure drop test which will be followed by tests to evaluate nozzle spray distribution and droplet size, exit temperature profiles, and emissions data. These will be conducted at sea level as well as at simulated cruise altitude for Overture at 60,000 ft.

The two-spool, medium-bypass turbofan engine will be equipped with a single-stage 72-in. dia. fan and optimized for prolonged supersonic operation with an air-cooled single-stage high-pressure turbine and three-stage low-pressure turbine. The Symphony’s compressor will be made up of a six-stage high pressure unit and a three-stage low pressure section, while the engine’s mixed compression supersonic inlet, diffuser and exhaust design is designed to meet Chapter 14 noise levels.