COMP 605 Final Project

Steady-state thermal analysis of an NRX-A6 nuclear thermal propulsion fuel element via parallel domain decomposition (RAS / ORAS / ASM).

Files:

File	Purpose
heat_ddm.edp	FreeFEM driver. Modes: 0=direct, 1=RAS, 2=ORAS, 3=ASM.
run_all.sh	Runs all five stages (~129 simulations). Restartable.
plot_results.m	MATLAB: generates all figures from results/.
results/	output results
figures/	output plots

Prerequisites:

• FreeFEM++ 4.x with PETSc, ffddm, iovtk modules (install)
• MPI runtime providing ff-mpirun (FreeFEM's installer bundles one)
• MATLAB R2019b+ (uses readmatrix, exportgraphics)
• LaTeX distribution (TeX Live / MiKTeX / MacTeX) for the report

Windows users: run run_all.sh from Git Bash, WSL, or MSYS2. FreeFEM, MATLAB, and LaTeX run natively on Windows.

Quick Reproduction

The repo ships with results/ and figures/ already populated. To regenerate end-to-end:

# 1) Run all simulations (~30-60 min depending on CPU; restartable).
chmod +x run_all.sh
./run_all.sh
# 2) Regenerate every figure.
matlab -batch plot_results
## To just rebuild figures from the shipped data
```bash
matlab -batch plot_results

Reads results/, writes figures/. Takes < 1 minute.

Notes:

• run_all.sh skips any run whose *_summary.txt already exists. Delete the relevant files (or the whole results/ directory) for a clean re-run.
• Stage breakdown: Stage 1 (3 direct runs), Stage 2 (60 ORAS overlap sweep), Stage 3 (45 runtime comparison), Stage 4 (6 alpha sweep), Stage 5 (15 tuned 3-way). Total ~129 FreeFEM invocations.
• Mode 0 (direct) is single-process by design; the script forces -np 1.
• Default mesh presets target ~93k / 265k / 564k elements. Exact triangle counts may vary slightly with FreeFEM build; adjust NE_LIST in run_all.sh to match precisely if needed.
• Environment on MS-MPI / Windows, (Mesh 3, N_D=6) and np >= 8 on Mesh 2/3 may fail; the script records the failure and continues. On Linux with OpenMPI/MPICH these typically run cleanly.