Found during the Phase-3 Riemann refactoring review (stacked PRs #1551-#1556 series).
Divergence (live behavior): HLLC applies the Rodriguez et al. (2019) elastic wave-speed correction (the (4G/3 + tau_e(dir_idx_tau(1)))/rho term in s_L/s_R, plus the stress-corrected s_S) under if (elasticity) — which covers hyperelastic runs, legal with HLLC. HLL has separate branches: its hypoelasticity branch uses the same tau_e algebra, but its hyperelasticity branch deliberately omits the tau_e term.
So a hyperelastic case run with HLLC vs HLL uses different wave-speed estimates as a matter of formulation, not scheme. One of these is presumably the intended physics for hyperelasticity.
Locations (post-#1556 module layout): src/simulation/m_riemann_solver_hllc.fpp elasticity blocks (~319-332, ~1354-1367); src/simulation/m_riemann_solver_hll.fpp hypo (~366-375) vs hyper (~376-380) branches.
Per maintainer decision (2026-06-11) both are left as-is pending a ruling from the elasticity model authors. Filing so it is tracked rather than folklore.
Found during the Phase-3 Riemann refactoring review (stacked PRs #1551-#1556 series).
Divergence (live behavior): HLLC applies the Rodriguez et al. (2019) elastic wave-speed correction (the
(4G/3 + tau_e(dir_idx_tau(1)))/rhoterm in s_L/s_R, plus the stress-corrected s_S) underif (elasticity)— which covers hyperelastic runs, legal with HLLC. HLL has separate branches: itshypoelasticitybranch uses the same tau_e algebra, but itshyperelasticitybranch deliberately omits the tau_e term.So a hyperelastic case run with HLLC vs HLL uses different wave-speed estimates as a matter of formulation, not scheme. One of these is presumably the intended physics for hyperelasticity.
Locations (post-#1556 module layout):
src/simulation/m_riemann_solver_hllc.fppelasticity blocks (~319-332, ~1354-1367);src/simulation/m_riemann_solver_hll.fpphypo (~366-375) vs hyper (~376-380) branches.Per maintainer decision (2026-06-11) both are left as-is pending a ruling from the elasticity model authors. Filing so it is tracked rather than folklore.