YJ-1S Engine Project

One of the biggest goals of the Yellow Jacket Space Program is to push the cutting edge of rocket development. This push is best embodied in our development of our first student engineered liquid rocket engine, the Yellow Jacket-1S, (YJ-1S). YJ-1S will be a sub-scale test article and it's the first liquid-fueled engine in developed by the YJSP team. The goal of the project is to develop a small scale, robust, test-focused engine, and doing so allows the team to rapidly iterate on the design of components to work towards increased performance through testing.

YJ1S v3.6.png

Technical Specifications

Engine Parameters

Thrust Chamber Pressure Isp (SL) C* (Characteristic velocity)
3500 N 18 Bar 244 s 1708 m/s
Fuel Oxidizer Fuel Flow Rate Oxidizer Flow Rate Oxidizer-to-Fuel Ratio
Jet-A LOX 0.53 kg/s 0.95 kg/s 1.8 to 1

Development Gallery

Testing Phases

YJ-1S Test Stand.png

1) Initial Cold Flow Testing - Throughout Spring '19 & Fall‘19
Practice safety procedures and cryogenic handling while verifying tank pressurization, sequencing, injector analysis (stiffness/flow resistance) and flow timing.


2) Heat Sink Static Fire - Target: November '19
Test injector, feed system, and igniter performance while demonstrating safe propellant handling, testing operation and regulation compliance.


3) Regeneratively Cooled Engine Flow Test - Target: Spring '20
Repeat cold flow testing with the regenerative cooling test article to verify hot fire timing.


4) Regeneratively Cooled Engine Static Fire - Target: April '20
Full sub-scale systems testing while demonstrating safe test operations.


Engine Design Code

To assist in the design of the YJ-1S engine, the propulsion team developed its own engine design software. The software utilizes user-generated NASA CEA data-decks to calculate the combustion product properties as well as perform geometric sizing on a desired combustor. Furthermore, the software is capable of full analysis of regenerative cooling circuits, allowing the team to design the engine thermal management systems. Some notional output plots from the baseline YJ-1S Design are shown below.

Engine Design Code Functional Diagram

Engine Design Code Functional Diagram

Hot gas convective heat transfer coefficient & total heat flux vs. chamber contour

Hot gas convective heat transfer coefficient & total heat flux vs. chamber contour

Hot-Wall, Cold-Wall, & Coolant bulk temperature vs. chamber contour

Hot-Wall, Cold-Wall, & Coolant bulk temperature vs. chamber contour


Contact

Trenton Charlson - Engine Development Lead - charlson.trenton@gatech.edu