Title: NASA’S COMPOSITE OVERWRAP LESSONS LEARNED ON 40K THRUST CHAMBER ASSEMBLIES

Authors: Allison M. Clark, Tyler B. Hudson, Cheol Park, Sandi G. Miller, Mike Goetz, Brandon Connell, Paul R. Gradl

DOI: 10.33599/nasampe/s.23.0147

Abstract: Filament wound carbon fiber/polymer composite overwraps combined with additively manufactured (AM) copper alloy combustion chambers are a critical part of NASA’s Rapid Analysis and Manufacturing Propulsion Technology (RAMPT) project. The composite overwrap is a high strength-to-weight material and allows for significant weight reduction of the high-pressure thrust chamber assembly, reduction of overall cost, and reduced fabrication time while offering structural robustness. Integrated AM/composite overwrap chamber assemblies using 907 kg (2,000 lbf (2k)) and 3200 kg (7,000 lbf (7k)) thrust were successfully hot fire tested at NASA Marshall Space Flight Center (MSFC). These assemblies allowed the team to learn lessons related to the design, analysis, and manufacturing of these integrated assemblies. A final goal of the RAMPT project is to design and test a 18100 kg (40,000 lbf (40k)) thrust chamber assembly. The 40k chamber presented the team several new challenges including an integral inlet port in the main body of the composite overwrap. Through multiple iterations of manufacturing techniques, varied materials, and Non-Destructive Evaluations (NDE), many lessons were learned to obtain a final design solution that would not only allow for the interrupted port inlet but also allow for sufficient material margins for the most critically stressed part of the chamber. This paper will cover the manufacturing techniques exploring fabric designs to help subsidize the coverage in the areas left bare by the inlet port during the filament winding process and custom tooling needed for the final full chamber processing. The original material choice of bismaleimide (BMI) 5250-4 from the 7k chamber performed well for the extreme environment of hot fire testing but proved to be difficult with the increased scale and interrupted port design of the 40k chamber. Discussion in this paper will cover these changes, including evaluation of the design, comparison to the prior 2k and 7k designs, and show the final hardware that will be tested. One primary goal of this work and RAMPT project is to provide this development process and data to industry for infusion into future engine designs.

References: 1. Protz, C.S., Gradl, P.R., Fikes, J., Garcia, C., Pelham, L., Clark, A., Hudson, T.B., Miller, S., Ogles, M., “Large-scale lightweight composite overwrap combustion chambers and nozzles under the rapid analysis and manufacturing propulsion technology (RAMPT project),” 2019 Joint Army-Navy-NASA-Air Force (JANNAF), 11th Liquid Propulsion Subcommittee (LPS) Proceedings, Tampa, FL, December 9-13, 2019. 2. Protz, C.S., W.C. Brandsmeier, K.G. Cooper, J.C. Fikes, P.R. Gradl, Z.C. Jones, C.R. Medina., D. L. Ellis, K.M. Taminger, “Thrust Chamber Assembly Using GRCOP-84 Bimetallic Additive Manufacturing and Integrated Nozzle Film Coolant Ring Supporting Low-Cost Upper Stage Propulsion,” 10th JANNAF Liquid Propulsion Subcommittee Meeting, Long Beach, CA, 2018. 3. Clark, A., Hudson, T.B., Miller, S., Edrington, S., Park, C., Protz, C., “Lightweight Thrust Chamber Composite Overwrap Lessons Learned,” The Composite and Advanced Materials Expo, Dallas, TX, 2021. 4. Gradl, P.R., Protz, C.S., Fikes, J., Clark, A., Evans, L., Miller, S., Ellis, D., Hudson, T.B., “Lightweight thrust chamber assemblies using multi-alloy additive manufacturing and composite overwrap,” AIAA Propulsion & Energy Forum Proceedings, New Orleans, LA, August 24-26, 2020. 5. Gibson, J.T., Gradl, P.R., Katsarelis, C.C., Teasley, T.W., Garcia, M.B., Clark, A.M., Stark, J.B., “Maturation and Hot Fire Testing of Additively Manufactured Bimetallic Composite Overwrap Thrust Chamber Assemblies,” 13th JANNAF Liquid Propulsion, 12th Spacecraft Propulsion Subcommittee Meeting, Huntsville, Al, 2022.

Conference: SAMPE 2023

Publication Date: 2023/04/17

SKU: TP23-0000000147

Pages: 16

Price: $32.00