High Frequency, High Resolution Infrared Health Management System for Rocket Engine Turbomachinery

The success of a launch depends upon the reliability of the launch vehicle, with the riskiest part of the vehicle being its rocket engine. For launch vehicles fueled by pump fed liquid propellants, the highest risk component is the turbomachinery, with the top two life issues being the turbine blades and bearings. These facts support the need for a fast, responsive and accurate health monitoring system (HMS) for turbopumps. Currently, there is no direct measurement of turbine blade or bearing health. FTT is developing an infrared (IR) HMS that measures temperatures during operation, thus detecting the first indicator of a fault. The results of the Phase I SBIR have shown the feasibility of applying a thermal optical IR sensor system to rocket engine turbomachinery health management. Testing conducted has demonstrated that a long-wave IR camera can “see through” a cryogenic liquid medium.The conceptual design of the miniaturized system illustrated examples of applying the sensor to monitoring in turbopumps- including turbine blades, bearings and inducers. The technical objective of Phase II is to advance the IR sensor system to somewhere between TRL 5-6. FTT proposes to do this by demonstrating the IR sensor system capability in an HCB risk reduction rig. BENEFIT: Anticipated benefits include extending the temperature range of the IR camera system, which would allow it to measure turbine blades in cooler environments, such as a LOX-rich staged combustion cycle or an expander cycle. Operating the IR sensor to look through a liquid medium would be another benefit that would allow measurements of the bearing inner raceway temperature changes of a relieved sleeve rolling element bearing. Additionally, improving the resolution of the IR sensor could allow it to detect the onset of cavitation in certain propellants by measuring the temperature drop from thermodynamic suppression head (TSH) effects. Successfully miniaturizing the IR camera system would allow it to be applied to on-line health management systems during flight, and the visual images it captures can be post-processed after flight determine on-condition maintenance actions. All these enhancements will serve improve the mission success rate of the launch vehicle, potentially saving millions in aborted launches or lost payload. The improved IR health management system allows improved measurement of industrial gas turbine systems as well. The results from the Phase I SBIR have shown that all previous anticipated benefits are indeed feasible goals- monitoring of lower temperature components, monitoring through cryogenic liquid media, and miniaturizing the system. Benefits from completion of Phase II would include advancing the technology to between TRL 5 and 6.