UCI Rocket Project

I am the Chief Engineer (previously lead propulsion engineer, propulsion engineer) on the UC Irvine Rocket Project! Leading UCI’s liquid rocketry team towards the goal of breaking the altitude record for undergraduate, methalox rockets! Most of my technical work over the past couple years was propulsion test related as we were working towards a successful vertical test fire and launch. Now post launch, the project is aiming higher with a new rocket, MOCH4. My technical work now is mainly focused on propulsion component design and system architecture for our next rocket! 🚀

MOCH4 Design

(Sep 2023-Present)

The following is some background and my contributions to UCI's second liquid rocket.

BTW - the inspiration behind the name MOCH4 (pronounced mocha☕) is that it continues the caffeine naming theme used throughout the project, and contains CH4 - methane - our fuel!

Propellant Tank Vent Valves

IN PROGRESS

I had end-to-end ownership over the design, manufacturing, and testing of custom propellant tank vent valves!

The propellant tank vent valves are the most extensive project I've worked on during my time on the rocket project. Therefore, they deserve their own page - link. This is my best work!

Project Description:

A vent valve is an On/Off valve between a propellant tank and the atmosphere that can be opened to evacuate boil off vapors during propellant filling and reduce tank pressure, and closed before flight in order to pressurize the propellant tanks.

The Preliminary Test Rocket used a ball valve and solenoid valve in parallel for venting. This implementation was suboptimal as the solenoid could actuate remotely and failed open, but had a tiny orifice and was inconsistent when flowing cryo vapor. The ball valve had a big orifice, but necessitated a risky operation to manually close the valves while the prop tanks were loaded.

The goal with my vent valve was to consolidate these into 1 valve that has a big orifice, can be remotely actuated, and fails open, all while reducing overall mass and packaging size. Check the vent valve page to see how it turned out!

In order to define system requirements and analyze system level performance of our next rocket MOCH4, we needed some way to quantitatively evaluate how changing specific vehicle parameters impacts our apogee - a main competition metric of collegiate rocketry.

The teams previous model was thought to be accurate, as it had predicted PTRs apogee within a few hundred feet; However, this was entirely a coincidence, as the dry vehicle mass used in these simulations was 75 lbs heavier than in real life! This was only uncovered after I led an effort to comprehensively re-mass everything on PTR.

The previous model was quite complex, computing various aerodynamic drag effects based on fin geometry etc, which made it difficult to detect where it was going wrong.

I set out to establish a very simplistic model based on fundamental kinematics that we could use to iterate through the key forces: weight, thrust, and drag, to provide insight into what changes will impact our altitude the most.

These sensitivity studies are shown below. Ultimately, this model showed that setting hard caps on vehicle diameter (8in) and mass (160lb) should push our next rocket past the methalox record.

Try on Google Colab

1D Trajectory Model

I wrote a custom python script based on fundamental time marching kinematics to model rocket trajectory. With PTR telemetry as an anchor, this tool was used to define MOCH4 goals and system requirements.

PTR predicted trajectory with model vs PTR recorded telemetry

Given the discrepancy between the model predicted apogee and the PTR apogee, the altitude goal was scaled to

ensure we don't overestimate our apogee with updated vehicle parameters.

AutoCEA.py

NASA CEA automation and data analysis python script - github link

Now post PTR launch, a lot of work is required to determine how much change is needed in order to produce a rocket capable of breaking the collegiate methalox altitude record.

We use NASA CEA to calculate combustion properties of our desired propellants with variable inputs with the goal of choosing a propellant mixture ratio to maximize Isp, but also not melt the engine.

It has been many years since Preliminary Test Engine design work took place, and the tools I could find from past years were pretty rudimentary. I am working on a set of propulsion design tools that will expedite our iteration process, better analyze theoretical data and scale to PTR performance, and more accurately predict trajectory/apogee. These tools will help us decide if we can meet our goals with PTE, or if engine redesign work is required, as well as being valuable assets for future years when blank slate engine design takes place.

Engineering Design Process (1).pdf

This document is not in its final form, but the critical information is present and has undergone thorough evaluation.

Engineering Design Process

I led the development and implementation of an engineering design process to provide structure to the UCIRP as the team enters the design phase for MOCH4.

Prior to the implementation of this design process, the UCIRP lacked a formal process for product development. This led to a lot of decisions made on the basis of "looks good enough" or "should be fine", which only propagated into bigger issues down the line. This design process also aimed to improve the quantity and quality of documentation, as well as familiarize the team with systems engineering.

One of my first steps was to review NASA's design process, and take bits and pieces to fit the scope of our project. I was also able to pull from my industry experience to compile the general structure shown in the diagram above. I then worked with others to define detailed entrance criteria for reviews, and split the whole system into discretized chunks to indicate requirement hierarchy and levels of ownership.

So far, this process has greatly improved the quality of our design, and should reduce the amount and severity of errors that slip through the cracks.

Preliminary Test Rocket (PTR) Launch

(Jan 2023 - Apr 2023)

On April 29, 2023 the UCI Rocket Project launched UCI’s first liquid rocket to ~9100 ft.

Derek Honkawa's video of our launch

Me standing awkwardly

next to PTR

Kyle Deck's onboard

camera footage

We launched in a 3 month turnaround from our final vertical test fire! The whole point of the vertical test fires is to validate the feed system in essentially as close to a launch configuration as possible. Therefore, the prop work during this time was to finalize the feed system and actually integrate with the complete vehicle structure. If I've learned anything from being on the rocket project, its that things are always harder than they seem upfront, and that issues are inevitable.

The PTR diameter was 11.5 inches - pretty large for its class, but considering this was the teams first rocket, not horrible. What was horrible was making all of the plumbing fit within the vehicle skin. We knew the plumbing config at VTF2 was slightly too bulky for launch, but thought it would be a couple re-routes and be done. Unfortunately, it required an almost complete reconfiguration of the pressure regulation and tank to injector plumbing.

My main responsibilities during this time were owning this plumbing reconfig task, determining tank pressure regulator set points based on head loss calcs on new plumbing, writing final launch procedures, directing final cold flow testing, creating detailed task and testing schedules leading up to launch, and of course functioning as test stand lead at our launch!

Launch config tank to injector (left) and pressurant (top) plumbing

This plumbing reconfiguration was one big spatial visualization puzzle. I had planned to reference and arrange in CAD, but our feed system assembly was too dissimilar to be helpful and would've taken too long to revise.

Launch Procedures (Spring 2023) (1).pdf

Launch Procedures

Propulsion specific launch week planning

Preliminary Test Rocket (PTR)
Vertical Test Fire 2

(Sep 2021-Jan 2023)

On January 21, 2023 the UCI Rocket Project successfully performed a static test fire on their Preliminary Test Engine with the entire feed system in vertical launch configuration.

Derek Honkawa's video

of VTF2

Me post fire!

Matthew Sprinkle's video

of VTF2

As most of my work on the project has been prop test focused, I have written lots of test procedures. These VTF2 procedures were obviously collaborative, but I wrote the large majority and validated/edited the procedure in cold flow testing.

Old Injector Plumbing

VTF2 Injector Plumbing

(Black insulated tubing)

Over Winter break 2022, I redesigned the test stand cart injector plumbing. This minimized complexity, reduced head loss between tank/injector, and reduced the number of potential leak points in the plumbing. This improvement eliminated the plumbing leakage issues we were having during cold flows! The most impressive part of this revision was my tube bending process. I don't know how the team bent 3/4" stainless in the past, but I was getting awful results using our tube bender. After countless rounds of trial and error, I discovered that putting 4 small squares of duck tape on the bending die at the tube locating hole preventing the tubes from denting, allowing me to complete the injector plumbing revision and aiding future 3/4" bending.

Cold Flow montage - I didnt realize it added music haha

A few pics from Vertical Test Fire 1. While the test was unsuccessful due to a valve failure, we were able to validate our procedures for future test fires.

Cold Brew Disassembly

I assisted in converting the plumbing from cold brew, our static test fire stand, to our rocket in vertical configuration for future Vertical Test Fires (VTF)

Injector Face during Cold Flow

In order to simulate flowing cryogenic propellants through our feed system prior to hot fire, we run cold flows with LN2. This also allows us to test all of our plumbing and instrumentation as well as practice test fire setup and procedures.

A little progression of the vertical assembly (top left → right → bottom left)

Underwater injector leak test

MVAS gear alignment/actuation test

Early-on Vertical Configuration at UCI Design Review

Early-on Vertical Configuration during Cold Flow

I helped reduce cost, weight, and total rocket length by optimizing physical plumbing configurations. I also chose necessary valves for tank venting based on safety considerations and trade study research