Add ES-DG optimized 3S* low-storage RK methods (Al Jahdali et al. 2022)#3241
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Add ES-DG optimized 3S* low-storage RK methods (Al Jahdali et al. 2022)#3241singhharsh1708 wants to merge 4 commits into
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ChrisRackauckas
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Rebasing SciML#3241 (approved months ago) over master exposed two breakages from unrelated drift, not merge conflicts: - thread::Thread = False() no longer resolves; the rest of the low-storage family moved to Serial() as the default. - SVector(...) was passed to LowStorageRK3SConstantCache, whose fields are NTuple; StaticArrays was never a runtime dependency, only a test one, so this never actually worked. Switched to plain tuples matching the sibling ParsaniKetcheson* constructors. Also Runic-reformats the added AlJahdali constructors (numeric literal style drifted from current convention); no other lines touched. Verified: all 16 methods solve, order-of-convergence matches each method's claimed order, and the full LowStorageRK Core suite passes (515 pass, 28 pre-existing broken, 0 fail).
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Rebasing SciML#3241 (approved months ago) over master exposed two breakages from unrelated drift, not merge conflicts: - thread::Thread = False() no longer resolves; the rest of the low-storage family moved to Serial() as the default. - SVector(...) was passed to LowStorageRK3SConstantCache, whose fields are NTuple; StaticArrays was never a runtime dependency, only a test one, so this never actually worked. Switched to plain tuples matching the sibling ParsaniKetcheson* constructors. Also Runic-reformats the added AlJahdali constructors (numeric literal style drifted from current convention); no other lines touched. Verified: all 16 methods solve, order-of-convergence matches each method's claimed order, and the full LowStorageRK Core suite passes (515 pass, 28 pre-existing broken, 0 fail).
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- Implement 16 new methods (advection- and vortex-optimized) - Reuse existing LowStorageRK3S cache structures (no allocations) - Add tableau constructors and alg_cache implementations - Register methods in alg_utils and exports - All tests pass (517 + JET + Aqua)
Rebasing SciML#3241 (approved months ago) over master exposed two breakages from unrelated drift, not merge conflicts: - thread::Thread = False() no longer resolves; the rest of the low-storage family moved to Serial() as the default. - SVector(...) was passed to LowStorageRK3SConstantCache, whose fields are NTuple; StaticArrays was never a runtime dependency, only a test one, so this never actually worked. Switched to plain tuples matching the sibling ParsaniKetcheson* constructors. Also Runic-reformats the added AlJahdali constructors (numeric literal style drifted from current convention); no other lines touched. Verified: all 16 methods solve, order-of-convergence matches each method's claimed order, and the full LowStorageRK Core suite passes (515 pass, 28 pre-existing broken, 0 fail).
The approved PR shipped with no test coverage for these methods at all. Adds a compact loop over all 16 checking convergence order against an analytic reference (test_problems_only_time), matching each method's alg_order. Unlike ParsaniKetchesonDeconinck3S*, these don't show a consistent +1 pure-quadrature super-convergence bump at the same dts range (some do, some measure close to their claimed order, some land between), so atol is looser (1.25) than the family's usual testTol (0.25) rather than hand-tuning dts per method. Still catches an actually wrong coefficient set, which would land further off.
Spell Check CI flagged every occurrence of Vor (the vorticity- optimized half of the AlJahdali 3S* family, paired with Adv for advection-optimized) as a typo for For.
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📌 Description
This PR adds 16 new 3S* low-storage explicit Runge–Kutta methods based on the work of Al Jahdali et al. (2022), designed for entropy-stable discontinuous Galerkin (ES-DG) discretizations.
The implemented methods include both:
Each method follows the existing 3S* low-storage formulation and integrates seamlessly with the current
OrdinaryDiffEqLowStorageRKinfrastructure.✨ What’s included
AlJahdaliAdv3S*(advection-optimized)AlJahdaliVor3S*(vortex-optimized)algorithms.jllow_storage_rk_caches.jlalg_utils.jlOrdinaryDiffEqLowStorageRK.jl(exports)🧠 Implementation Details
LowStorageRK3SConstantCacheLowStorageRK3SCacheperform_step!for 3S* methods (no changes required)🧪 Testing
No regressions observed.
✅ Checklist
🔗 Additional context
Implements methods discussed in issue #2903.
These methods extend the solver suite with problem-specific optimized integrators for high-order DG discretizations, particularly useful in compressible flow and wave propagation problems.