Nonlinear Heat — Temp-Dependent Conductivity (dim=40)

ADVANTAGES2 · dim 40

SolvSRK wins. At the comparison noise level, SolvSRK beats the best baseline by at least 10 percentage points of survival, or by at least 0.05 balanced score when survival is tied. Use SolvSRK for this class of problem. All verdicts →

Same two-layer geometry as ir_two_layer_heat but with temperature-dependent diffusivity: alpha(T) = alpha_ref * (1 + beta*(T - T_ref)), beta=0.005 K^-1. The state-dependent system matrix makes this LRDE-ineligible. Tests the boundary of LRDE applicability: identical geometry, nonlinear physics.

Thermal & heat transfer

Problem definition

Incropera & DeWitt, Fundamentals of Heat Transfer, 7th ed.; Mills, Heat Transfer, 2nd ed.

Canonical RHS excerpt from the registered callable used for this benchmark cell. Expand it to verify the state equations; it is not a standalone runnable fixture.

Show canonical RHS excerpt
def rhs(t: float, temp: np.ndarray) -> np.ndarray:
    temp = np.clip(np.asarray(temp, dtype=float), 200.0, 3500.0)
    d = np.zeros(n)
    for i in range(n):
        alpha_i = alpha_ref[i] * (1.0 + beta * (temp[i] - t_ref))
        t_left = 400.0 if i == 0 else temp[i - 1]
        t_right = 300.0 if i == n - 1 else temp[i + 1]
        d[i] = alpha_i * (t_left - 2.0 * temp[i] + t_right) / dx2
    return d
Parameters
  • alpha_ref = [0.0001, 0.0001, 0.0001, 0.0001, 0.0001, 0.0001, …] [shape=(40,), min=1e-06, max=0.0001]
  • beta = 0.005
  • dx2 = 6.25e-08
  • n = 40
  • t_ref = 350
Initial condition
y(0) = [400, 397.435897436, 394.871794872, 392.307692308, 389.743589744, 387.179487179, …] [shape=(40,), min=300, max=400]
Horizon
t ∈ [0, 20]

Canonical RHS excerpt captured from the same registered callable used for the published benchmark. Frozen closure values are summarized below; helper imports and solver settings are intentionally omitted.

Fingerprint

Spread: high

Default noise: none

Recommendation snapshot

Clean best: SolvSRK

Noisy best: SolvSRK

Coverage

14 solver arms · clean + 5 noise levels

Ranked on survival, precision, and speed

Versions & freeze

Methodology →
Freeze
2026-08-13
libsolvsrk
2.3.0
SciPy
1.14
SUNDIALS
CVODE (bundled backend)

20 seeds/cell default · 14 arms · TRL 4–5 · simulation-lab validated · this page: Nonlinear Heat — Temp-Dependent Conductivity (dim=40) (nonlinear-heat-temp-dependent-conductivity-dim-40)

Governed SolvTune benchmark freeze; per-arm medians only. RHS definitions and raw trial rows are not published.

Self-reported by Resonix Labs · not independently verified

Results matrix

Pick an objective and a noise level to rank all arms on survival, median SCD, median nfev, and median wall time. Medians across seeds.

Objective

Best overall trade-off of survival, precision, and speed.

Noise level

#SolverSurvivalSCDnfevWallScore
1SolvSRK
100%
11.51,61965 ms0.892
2SciPy RadauSciPy
100%
10.880048 ms0.877
3SciPy LSODASciPy
100%
8.91,54458 ms0.831
4SciPy DOP853SciPy
100%
8.8280,45411.54 s0.828
5SciPy RK45SciPy
100%
8.7315,74613.24 s0.826
6Tsit5external
100%
8.6325,06842.00 s0.824
7CVODE BDFexternal
100%
8.641624 ms0.823
8SciPy BDFSciPy
100%
8.247334 ms0.814
9CVODE Adamsexternal
100%
8.21,57571 ms0.814
10SciPy RK23SciPy
100%
7.9178,4097.87 s0.806

At Clean, best balanced arm is SolvSRK.

Values are medians across seeds, measured by Resonix Labs on Resonix hardware and not independently verified; nfev and wall are on reference lab hardware (indicative). Under injected noise only SolvSRK and the SciPy arms are run. How we measure accuracy → · Verification status →

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Cite this page

Replace the access date. Pin the freeze ID and library versions when comparing against a later export. Cite it as what it is — a self-reported vendor benchmark, not an independently verified result. The note field says so; please keep it.

@misc{resonix_evidence_nonlinear_heat_temp_dependent_conductivity_dim_40_2026,
  title        = {Resonix Evidence Portal: Nonlinear Heat — Temp-Dependent Conductivity (dim=40)},
  author       = {{Resonix Labs (Canada) Inc.}},
  year         = {2026},
  howpublished = {\url{https://resonix.tech/evidence/problems/nonlinear-heat-temp-dependent-conductivity-dim-40}},
  note         = {Self-reported vendor benchmark; internally generated by Resonix Labs and not independently verified. Accessed YYYY-MM-DD. Freeze 2026-08-13; libsolvsrk 2.3.0; SciPy 1.14.}
}

Related

TRL 4–5 · simulation-lab validated · 398 problems · 14 solver arms · clean + 5 noise levels

Freeze: 2026-08-13 · scipy 1.14 · libsolvsrk 2.3.0 · Methodology

Self-reported by Resonix Labs · not independently verified · Verification status