Spring 2023

During the Spring of 2023, Stellar has made significant progress on the Engineering Design and Controls teams, working on injector testing and fluid feed system assembly.

Goals

This semester our goal was to test our injector using the full fluid flow rate and document and analyze our findings from the result. Another goal was to redesign the chamber and nozzle component to fit within the size constraints of the metal 3D printer in the Additive Manufacturing Lab here at Iowa State and implement cooling channels with accurate wall thicknesses. On the controls team’s side of the project, we researched pressure vessels and cryogenic hardware components, documented our findings, and developed a list of recommended hardware for purchasing in future semesters. Furthermore, another goal for the controls team is to construct the Fuel side of the fluid feed system, connect the necessary components to the lab view, and test the system. Finally, in preparation for the future of Stellar, we wanted to start communications with EH&S and the University about developing a testing area and future steps they want us to take regarding hot-fire testing.

Deliverables

This semester, Stellar had five deliverables:

• Redesign Chamber and nozzle with more accurate regenerative cooling channels and smaller form factor.
• Conduct and analyze Full Flowrate Cold Flow Injector Tests
• Create a report on pressure vessel options and recommendations for future purchase
• Create a report on cryogenic hardware and recommendations for future purchase
• Assemble 1st half of the fluid feed system in Pathfinder

At the time of this post, we have completed two deliverables. These two deliverables are the report on pressure vessels and cryogenic hardware. The remaining three to be completed are the chamber and nozzle redesign, the injector tests, and the assembly of the fluid feed system.

Remaining Work for the Semester

Regarding future work to complete the remaining deliverables, completing the regenerative cooling channels is the only thing holding back the chamber and nozzle redesign. Once the cooling channel design and wall thicknesses are determined, the model of the chamber and nozzle can be completed. Finally, for the fluid feed system, the controls team is working on the physical assembly and the LabView code to go along with it.

Fall 2022

During the 2022 Fall semester, students have made significant progress towards our goal of preparing one line of flow for assembly next semester, preparing for metal 3D printing nozzle and injector, and testing pintle injector designs.

The Controls Team has researched and ordered turbine flow meters, check valves, pressure relief valves, and globe valves for the fluid feed system of Pathfinder. The controls team has also created a working electrical circuit with LEDs and potentiometers representing each sensor and valve in the fluid feed system for Pathfinder. It has also calculated the theoretical pressure and temperature across the fluid feed system. The controls team has written reports on the testing procedures and usage of the pressure transducer, solenoid valve, flow meter, pressure relief valve, pressure regulator, globe valve, and check valve. The controls team has also tested the stepper motor and solenoid valves ordered in the previous semester.

The Engineering Design team has created new CAD models for the nozzle and injector of the engine. The nozzle is now shaped as a proper converging-diverging nozzle with regenerative cooling channels, and this model has been 3D printed. The injector design has been recreated for fluid-on-fluid contact in a more simple, manufacturable design than the first iteration. This model has been 3D printed and will be tested on the week of November 28^th. The Engineering Design team has also contacted Iowa State and commercial metal 3D printing resources and has written a report detailing metal 3D printing pricing, materials, choices, and justifications.

Currently, the Controls team is working on testing the pressure sensor ordered in the previous semester. The Engineering Design team is working on testing the spray characteristics of the 3D-printed pintle injector. Both tests will take place on November 28^th, so wait for an update after that week for more information on these tests.

Injector Cross-Section | Full Injector | Thrust Chamber Cross-Section

Students at STELLAR conducted a presentation at the M:2:I Design Expo on December 7th, 2021. STELLAR showcased the latest developments regarding the design of Typhoon 1.0 and the development of Pathfinder. The presentation featured the latest CAD model detailing the development of Pathfinder as well as the first iteration of the Thrust Chamber design with an integrated Regenerative Cooling System. STELLAR also showcased a 3D printed design for the current iteration of the Pintle Injector, which will be affixed to the Fluid Feed System. STELLAR plans on consistently iterating the design of the Thrust Chamber, Nozzle, and Pintle Injector until the performance requirements are met. Starting in Spring 2022, STELLAR will advance the development of the Pintle Injector and the design of the Thrust Chamber and Nozzle with an integrated Regenerative + Film Cooling System.