Design and Analysis of Metal-to-Composite Nozzle Extension Joints

As the operational demands of liquid rocket engines increases, so too does the need for improved design and manufacturing methods for metal-to-composite nozzle extensions. The state of the art utilizes non-domestic composite materials for nozzle extensions. Although this solution does offer weight savings and increased performance, there is an increase in cost and the addition of Export regulations. Within this effort, Materials Research & Design (MR&D) is proposing an analytical study, coupled with subcomponent fabrication and testing, that would result in a design for a domestically available C-C nozzle extension and metallic-to-composite joint for the J-2X. The proposed study would investigate various mechanical attachment methods, such as mechanical fasteners and adhesives for both the CMC-to-metallic joint and the CMC-to-CMC joint. Additional aspects of the trade study would investigate various flange shapes and materials in order to reduce the critical stresses in the region.

In addition to liquid rocket engine nozzle extensions, the technology developed within this effort would benefit any application that requires a metal-to-composite joint that operates under extreme thermal conditions. Letters of support from ATK and Pratt & Whitney Rocketdyne (Included in Part 12 of the proposal) support the application of the proposed technology for future propulsion system designs.

Nozzle extensions are utilized on many rocket engines that require increased thrust and specific impulse. For large scale engines, there is currently no domestically available technology capable of meeting the operational needs. The technology developed here will have a direct impact on the design and manufacturing of metal-to-composite nozzle joints for all future propulsion system designs by offering a domestically available alternative to the non-domestic state-of-the-art. Although the proposed effort will focus on the J-2X engine design and loads, the developed technology could also be applied to the RL 10B-2 cryogenic application since the CTE issues are present in both cases.

This is early/mid-stage (TRL 3) — the most realistic path in is NASA SBIR/STTR, which funds small businesses and research institutions to develop technology aligned with NASA's needs (equity-free, phased funding). Check whether a current SBIR/STTR solicitation topic overlaps with this project's technology area, or contact the project directly (above) to ask.

None of these are guaranteed paths for this specific project — TechPort itself doesn't have an "apply" button. Reaching out to the contact(s) above with a specific question is usually the fastest way to find out what's actually open.