init

Author: LEJMO

README.md

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+# diffHeatTO
+
+A modular differentiable multi-physics framework in JAX for coupled thermal-fluidic-structural topology optimization.
+
+## Overview
+
+- Couples Stokes-Brinkman, conjugate heat transfer, and linear thermoelasticity
+- Reverse-mode AD with custom VJP rules (no manual adjoint derivation)
+- Sparse solver backend: O(n^1.1) scaling in 2D, GPU-native CG for 3D
+- Warm-start strategy enables three-physics optimization where cold-start fails
+
+## Installation
+
+```bash
+pip install jax==0.4.30 jaxlib==0.4.30 scipy==1.12.0 numpy==1.26.4 pyamg==5.2.1 matplotlib
+```
+
+## Quick Start
+
+```bash
+# Run 2D warm-start benchmark (80x40 mesh, ~3 min)
+python src/benchmarks/run_benchmark_v2.py
+
+# Run aluminum material validation
+python src/benchmarks/run_aluminum_validation.py
+
+# Validate Stokes assumption
+python src/benchmarks/validate_stokes.py
+```
+
+## Project Structure
+
+```
+src/
+├── solvers/                # Physics solver modules
+│   ├── fem.py              # 2D FEM infrastructure (Q4 elements)
+│   ├── fem3d.py            # 3D FEM (H8 elements)
+│   ├── fem3d_q2q1.py       # 3D Taylor-Hood Q2-Q1 elements
+│   ├── fluid.py            # Stokes-Brinkman solver (2D)
+│   ├── fluid_3d.py         # Stokes-Brinkman solver (3D)
+│   ├── thermal.py          # Conjugate heat transfer
+│   ├── structural.py       # Linear elasticity + thermal stress
+│   ├── coupled.py          # 2D coupled multi-physics pipeline
+│   ├── heat_sink_solver.py # 2D integrated multi-physics
+│   ├── heat_sink_3d.py     # 3D integrated multi-physics
+│   ├── sparse_solve.py     # Sparse solver + custom VJP (CPU)
+│   ├── gpu_solve.py        # GPU-native CG solver + custom VJP
+│   ├── gpu_stokes.py       # GPU Schur complement for Q2-Q1
+│   └── stokes_coupled.py   # 3D Schur complement (CPU)
+├── optimization/           # SIMP, filtering, MMA, warm-start
+│   ├── optimizer.py        # Main optimization loop + warm-start scheduler
+│   ├── mma_optimizer.py    # Method of Moving Asymptotes
+│   ├── al_optimizer.py     # Augmented Lagrangian optimizer
+│   └── filters.py          # PDE-based filtering + Heaviside projection
+├── benchmarks/             # Reproducible experiment scripts
+│   ├── run_benchmark_v2.py # Primary 2D warm-start benchmark
+│   ├── run_3d_optimization.py
+│   ├── run_3d_large_gpu.py
+│   ├── run_beta_ablation.py
+│   ├── run_3d_beta_ablation.py
+│   ├── run_aluminum_validation.py
+│   ├── validate_stokes.py
+│   ├── run_robustness_study.py
+│   ├── run_warmstart_benchmark.py
+│   ├── run_gpu_benchmark.py
+│   ├── run_profiling.py
+│   ├── benchmark_mesh_convergence.py
+│   └── ...                 # Additional benchmarks and tests
+├── analysis/               # Paper figure generation
+│   ├── generate_paper_figures_v4.py
+│   ├── generate_methodology_figures.py
+│   └── generate_arch_figure.py
+├── surrogate/              # Surrogate model experiments
+│   ├── generate_data.py
+│   ├── train_surrogate.py
+│   └── generate_figures.py
+└── utils/                  # Visualization, I/O
+    └── visualization.py
+results/                    # Pre-generated data (JSON, NPY)
+paper/                      # LaTeX manuscript + figures
+```
+
+## Reproducing Paper Results
+
+Total reproduction time: ~10-12 hours (CPU), ~14 hours for 3D GPU case.
+
+See `src/benchmarks/` for individual experiment scripts.
+
+## Hardware
+
+- CPU: Intel Xeon W-2245 (3.9 GHz, 8 cores, 64 GB RAM)
+- GPU: NVIDIA Quadro RTX 5000 (16 GB) -- for 3D 40x40x20 case
+
+## Citation
+
+[Paper citation to be added upon publication]
+
+## License
+
+MIT

src/__init__.py

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+# diffHeatTO: Differentiable Multi-Physics Topology Optimization