Fluid Network Analysis | Yellow Jacket Space Program

Project Overview

This project was completed as part of the technical onboarding for the Vespula propulsion subteam. The goal was to design and model a fluid system to deliver water at a mass flow rate between $40-50~\text{kg/s}$.

The simulation methodology is based on the Finite Volume Procedure described by Alok Majumdar (NASA/Marshall Space Flight Center) in "A Finite Volume Procedure for Thermo-Fluid System Analysis in a Flow Network". This approach solves mass and energy conservation at system nodes and momentum conservation across branches.

Project Deliverables

As specified in the Project Description, this analysis provides:

1. Transient State Variables: Pressure, internal energy, and enthalpy for each node.
2. Transient Flow Properties: Volumetric and mass flow for each branch.
3. Steady-State Analysis: Calculation of the time required to reach relative steady state.
4. Safety Margins: Factors of Safety (FoS) for all components, lines, and orifices.
5. System Pressure Ladder: A full breakdown of pressure drops across the network.
6. System Curves: Characterization of the architecture for tank pressures up to $285.3~\text{psig}$.

The Two-Sim Strategy

Because fluid capacitance ($C$) for water is extremely low ($2.879 \times 10^{-8} \text{ kg/Pa}$), traditional explicit numerical methods require a tiny time step ($\Delta t < 9.5 \times 10^{-3} \text{ s}$) to remain stable. To optimize efficiency, I implemented a dual-simulation approach:

• Sim A (Inflated Capacitance): Uses increased capacitance to reach steady state rapidly and generate the system pressure ladder.
• Sim B (Physical Capacitance): Uses results from Sim A as initial conditions to capture high-fidelity transient data during the first $100 - 200 \text{ ms}$ of flow.

Key Results

• Performance: Achieved a steady-state mass flow of $\dot{m} \approx 49.55~\text{kg/s}$.

• Structural Integrity: System maintains a Pipe FoS of $14.8$ and a Valve FoS of $2.8$.
• Pressure Distribution: The butterfly valve accounts for $61.2%$ of the total system pressure drop.

Tip

For a full breakdown of these results and their engineering implications, refer to the Technical Presentation located in the /docs folder.

Repository Content

• /code: MATLAB scripts for Sim A and Sim B architectures.
• /docs: Includes the technical presentation, the Majumdar reference paper, and the original Project Description.
• /plots: Visualizations of pressure ladders and transient flow behavior.

How to Run

1. Open MATLAB and navigate to the /code directory.
2. Download and Run SimulationScript.m to execute the simulation.
3. Figures and Plots will generate automatically within 1-2 minutes on the higest fidelity setting (see line 159).