Design and Construction of a Hybrid Rocket Propulsion System Project Lead: Dalko H. Jeri Co-leads: Grant Neville, Thomas Martinez Senior Members: Thierry Lem, Harrison Rhein, Phung Chinh, Hayden Smith, Yuanrui Wang. Junior Members: Zach Meinert, Marcos Lipic, Will Lindsay. MECH 4045-002: Senior Design II Professor Doug Gallagher May 06, 2020 2 Abstract The main objective of RocketLynx is to design, build, and test a lightweight hybrid rocket propulsion system. This hybrid rocket engine was designed to be capable of producing a peak thrust 250 lbs. in a 10-second static fire. This rocket engine is designed around Spaceport America Cup requirements, since one of our long-term objectives is to eventually participate in this competition with a similar engine. Spaceport America Cup is one of the largest intercollegiate and international rocket competitions in the world happening every summer in White Sands, NM. The hybrid rocket engine consisted of an oxidizer based on Nitrous Oxide, also known as NOS, and hydroxyl-terminated polybutadiene as a solid fuel, also known as HTPB. The project was divided into different sub-teams according to the different components of the engine: the oxidizer, combustion, nozzle, manufacturing, and data acquisition. RocketLynx also built its own test stand apparatus consisting of a steel frame, a load cell, and linear bearings which was responsible for measuring the thrust produced by the engine. A monitoring system was also developed and integrated in order to keep record of the temperatures and heat transfer from the combustion process to the combustion housing. This system was integrated in order to protect the structural integrity of the housing from thermal shocks that resulted in creep. The short-term objective was to conduct a static fire test by the end of March 2020. Since the pandemic shut down campus and other facilities necessary for the completion of our static fire test, the project was halted in the middle of the manufacturing phase. This report reflects only the work of our team done from January to early March of 2020. 2 Acknowledgements Thanks to our advisors: John from TRIPOLI, Juan Rodelo, Eric Hernandez, Rudy for the website, Nicholas T, and Hans, Terry, and James from the Machine and Elec Shops at JILA for their endless support and resources. This work is dedicated to the countless hours each of us spent away from our loved ones, to sleepless nights, and to the red vines with pretzels dinners. The work is also dedicated to our junior members, especially Marcos, Zach, and Will, who will continue the legacy of RocketLynx, paving the road to the Spaceport America Cup. 2 Table of Contents Abstract . 1 List of Figures . 4 List of Tables . 5 Introduction . 8 Chapter 1 Initial Considerations . 9 Chapter 2: Oxidizer Subsystem . 12 Chapter 3: Combustion Chamber Housing Subsystem . 14 Chapter 4: Fuel Grain Subsystem . 25 Chapter 5: Supersonic Nozzle . 31 Chapter 6: Test Stand and Data Acquisition . 36 Chapter 7: Manufacturing . 39 Chapter 8: Test Plans . 48 Chapter 9: Path Forward . 49 References . 50 Appendices . 51 2 List of Figures Figure 1 . 15 Figure 2 . 18 Figure 3 . 18 Figure 4 . 20 Figure 5 . 22 Figure 6 . 23 Figure 7 . 24 Figure 8 . 26 Figure 9 . 27 Figure 10 . 27 Figure 11 . 29 Figure 12 . 30 Figure 13 . 32 Figure 14 . 32 Figure 15 . 33 Figure 16 . 34 Figure 17 . 35 Figure 18 . 35 Figure 19 . 37 Figure 20 . 37 Figure 21 . 39 2 Figure 22 . 40 Figure 23 . 41 Figure 24 . 42 Figure 25 . 43 Figure 26 . 44 Figure 27 . 45 Figure 28 . 46 Figure 29 . 47 2 List of Tables Table 1 . ..