APTU Combustion Health Monitoring

OUSD (R&E) CRITICAL TECHNOLOGY AREA(S): Hypersonics The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), 22 CFR Parts 120-130, which controls the export and import of defense-related material and services, including export of sensitive technical data, or the Export Administration Regulation (EAR), 15 CFR Parts 730-774, which controls dual use items. Offerors must disclose any proposed use of foreign nationals (FNs), their country(ies) of origin, the type of visa or work permit possessed, and the statement of work (SOW) tasks intended for accomplishment by the FN(s) in accordance with the Announcement. Offerors are advised foreign nationals proposed to perform on this topic may be restricted due to the technical data under US Export Control Laws. OBJECTIVE: Develop a nonintrusive diagnostic health-monitoring system for real-time detection of combustor hardware failure. DESCRIPTION: The Aerodynamic and Propulsion Test Unit (APTU) at the Arnold Engineering Development Complex (AEDC) is a hypersonic test facility that produces a true flight conditions (temperature and pressure test environment) via combustion. The high-temperature, high-pressure combustion chamber environment is severe and combustion chamber components can fail rapidly. The combustion chamber components are constructed of copper and Monel. Failures in the combustion chamber generally result in the destruction of one or more of these components. It is known from video camera recordings that fragments of these failed components are observable at the exit plane of the expansion nozzle. It is suspected, but not verified, that atomic and molecular species from the failed components will be present in the nozzle effluent. A nonintrusive, real-time, diagnostic health-monitoring system is needed for immediate detection of combustor hardware failure and shutdown of the combustor to minimize facility damage. Since damage starts in a localized part inside the combustion chamber, nonintrusive health monitoring technologies must have wide viewing angles or multiple sensors to cover the wide extent of the flow field and capture problems early. PHASE I: Develop understanding of the APTU combustor operation and materials and the supersonic-to-hypersonic flow field at the exit of the facility nozzle. Assess nonintrusive diagnostic systems and select those that are expected to work for an APTU-type flow field. This includes high velocity flow with high total temperature and pressure, and water vapor condensation. Perform bench-top combustion studies on the response of the chosen systems to Monel and copper spectrum. PHASE II: Develop a nonintrusive diagnostic-type health monitoring prototype and demonstrate the capability in a flow field environment to the one found at the exit of the free jet nozzle in APTU. A smaller-than-APTU scale test rig is acceptable if localized sources of material can be vaporized and detected across the full diameter of the nozzle exit. PHASE III DUAL USE APPLICATIONS: Potential Phase III efforts include full production capability in hydrocarbon combustion chambers such as coal-fired powerplants and gas turbine engines; rocket engines; and other high-enthalpy ground test facilities such as arc heaters. REFERENCES: 1. Test Facility Guide Arnold Engineering Development Complex, [online document], URL: http://www.arnold.af.mil/Portals/49/documents/AFD-080625-010.pdf?ver=2016-06-16-100801-260 [cited 20 January 2021]. KEYWORDS: Combustion Systems Health Monitoring; Nonintrusive Diagnostics