Add convergence-rate CI for WENO5/3/1 and MUSCL2

.github/workflows/convergence.yml

@@ -0,0 +1,60 @@
+name: Convergence
+
+on:
+  push:
+  workflow_dispatch:
+
+jobs:
+  convergence-1d:
+    name: "1D Advection Convergence"
+    runs-on: ubuntu-latest
+    timeout-minutes: 60
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Setup Ubuntu
+        run: |
+          sudo apt update -y
+          sudo apt install -y cmake gcc g++ python3 python3-dev \
+                   openmpi-bin libopenmpi-dev
+
+      - name: Setup Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.12"
+
+      - name: Initialize MFC
+        run: ./mfc.sh init
+
+      - name: Run 1D convergence tests
+        run: |
+          python toolchain/mfc/test/run_convergence_1d.py \
+            --resolutions 128 256 512 1024
+
+  convergence-2d:
+    name: "2D Isentropic Vortex Convergence"
+    runs-on: ubuntu-latest
+    timeout-minutes: 60
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Setup Ubuntu
+        run: |
+          sudo apt update -y
+          sudo apt install -y cmake gcc g++ python3 python3-dev \
+                   openmpi-bin libopenmpi-dev
+
+      - name: Setup Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.12"
+
+      - name: Initialize MFC
+        run: ./mfc.sh init
+
+      - name: Run 2D convergence tests
+        run: |
+          python toolchain/mfc/test/run_convergence.py \
+            --resolutions 32 64 128

docs/documentation/case.md

@@ -445,6 +445,7 @@ See @ref equations "Equations" for the mathematical models these parameters cont
 | `mp_weno`                  | Logical | Monotonicity preserving WENO |
 | `muscl_order`              | Integer | MUSCL order [1,2] |
 | `muscl_lim`                | Integer | MUSCL Slope Limiter: [1] minmod; [2] monotonized central; [3] Van Albada; [4] Van Leer; [5] SUPERBEE |
+| `muscl_eps`                | Real    | MUSCL limiter slope-product threshold (default: hard-coded thresholds; set to 0 for textbook behavior) |
 | `flux_lim`                 | Integer | Flux limiter for post-process: [1] minmod; [2] MUSCL; [3] OSPRE; [4] SUPERBEE |
 | `int_comp`                 | Logical | THINC Interface Compression |
 | `ic_eps`                   | Real    | Interface compression threshold (default: 1e-4) |
@@ -542,6 +543,10 @@ It is recommended to set `weno_eps` to $10^{-6}$ for WENO-JS, and to $10^{-40}$
 - `muscl_lim` specifies the slope limiter that is used in 2nd order MUSCL Reconstruction by an integer from 1 through 5.
 `muscl_lim = 1`, `2`, `3`, `4`, and `5` correspond to minmod, monotonized central, Van Albada, Van Leer, and SUPERBEE, respectively.
 
+- `muscl_eps` controls the slope-product activation threshold for all MUSCL limiters.
+When not set (default), the threshold is 1e-9 for minmod/MC, and 1e-6 for others.
+Setting `muscl_eps = 0` gives textbook limiter behavior where limiters activate whenever both slopes have the same sign.
+
 - `int_comp` activates interface compression using THINC used in MUSCL Reconstruction, with control parameters (`ic_eps`, and `ic_beta`).
 
 - `riemann_solver` specifies the choice of the Riemann solver that is used in simulation by an integer from 1 through 4.

docs/index.html

@@ -58,6 +58,7 @@
             { name: "Mach 0.3 flow over a corgi (2M STL)", image: "res/simulations/u.png", computer: "HiPerGator", computerUrl: "https://www.rc.ufl.edu/about/hipergator/",                                     accelerators: "2 GPUs",    walltime: "80s",  source: "https://www.youtube.com/watch?v=O8dSRqHLp_o" },
             // Shock-droplet
             { name: "Shedding water droplet",              image: "res/simulations/a.png", computer: "Summit",     computerUrl: "https://www.olcf.ornl.gov/summit/",                                            accelerators: "960 V100s", walltime: "4h",   source: "https://www.youtube.com/watch?v=Gjj-qZkXcrg" },
+            { name: "1K resolved particles",               image: "res/simulations/x.jpg", computer: "Phoenix",    computerUrl: "https://www.pace.gatech.edu/",                                                 accelerators: "4 A100s",   walltime: "~1.5h", source: "https://www.youtube.com/watch?v=ufisHG0KkOU" },
             // Biomedical & acoustics
             { name: "Burstwave lithotripsy",               image: "res/simulations/k.png", computer: "Delta",      computerUrl: "https://www.ncsa.illinois.edu/research/project-highlights/delta/",              accelerators: "128 A100s", walltime: "30m",  source: "https://www.youtube.com/watch?v=XWsUTaJXGF8" },
             { name: "Cavitation fragments kidney stone",   image: "res/simulations/d.png", computer: "Summit",     computerUrl: "https://www.olcf.ornl.gov/summit/",                                            accelerators: "576 V100s", walltime: "30m",  source: "https://doi.org/10.48550/arXiv.2305.09163" },
@@ -74,6 +75,7 @@
             { name: "Breakup of vibrated interface",       image: "res/simulations/f.png", computer: "Summit",     computerUrl: "https://www.olcf.ornl.gov/summit/",                                            accelerators: "128 V100s", walltime: "4h",   source: "https://www.youtube.com/watch?v=XQ3g1oSg8mc" },
             { name: "Viscous Taylor-Green vortex",         image: "res/simulations/h.png", computer: "Delta",      computerUrl: "https://www.ncsa.illinois.edu/research/project-highlights/delta/",              accelerators: "128 A100s", walltime: "17h",  source: "https://www.youtube.com/watch?v=7i2h08dlDQw" },
             { name: "Mach 1.5 shock-helium bubble",        image: "res/simulations/t.png", computer: "Phoenix",    computerUrl: "https://www.pace.gatech.edu/",                                                 accelerators: "1 A100",    walltime: "1h",   source: "https://www.youtube.com/watch?v=zDJoe0NYZsQ" },
+            { name: "Sphere collision and wall rebound",   image: "res/simulations/w.jpg", computer: "Phoenix",    computerUrl: "https://www.pace.gatech.edu/",                                                 accelerators: "4 A100s",   walltime: "~2h",   source: "https://www.youtube.com/watch?v=5ugLuDtV0C0" },
         ];
 
         const scalings = [