Pith. sign in

REVIEW 4 major objections 5 minor 103 references

Large-Scale Topology Optimisation of Time-dependent Thermal Conduction Using Space-Time Finite Elements and a Parallel Space-Time Multigrid Preconditioner

T0 review · 4 major / 5 minor · reviewed 2026-08-05 · deepseek-v4-flash

Pith's one-line read Treating time as a spatial dimension and solving the whole transient heat-conduction problem at once with a space-time multigrid preconditioner cuts time-to-solution for thermal topology optimization by up to 52x and scales to 4.2 billion d

desk verdict Solid proof-of-concept with a defensible ~20x speed-up; the 52x headline rests on a baseline that was never actually run. read the letter →

arxiv 2508.09589 v1 pith:A42FLPQF submitted 2025-08-13 cs.CE math.OC

classification cs.CEmath.OC MSC 65M6065F1065Y0574P15
keywords topologyoptimizationspace-timefiniteelementsmultigridparallel-in-timetransientheatconductionsemi-coarseninglarge-scalecomputingadjointsensitivityanalysis
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

This paper is a proof-of-concept for a parallel-in-time route to transient thermal topology optimization: instead of walking through time one step at a time, it discretizes the transient heat equation on a space-time mesh and solves the entire (2+1)-dimensional problem as one large linear system. The solve is handled by a Krylov method preconditioned with a space-time multigrid V-cycle whose coarsening direction is chosen by the local anisotropy of the diffusion problem. On two benchmark problems, the authors report wall-clock reductions over a backward-Euler time-stepping reference of up to 52x, at 2.4x to 7.7x the core-hour cost, and they solve systems with up to 4.2 billion unknowns in roughly 17 minutes on a distributed-memory machine. If these numbers transfer beyond the two benchmarks, the method offers a credible way to optimize time-dependent designs at scales previously reserved for static problems.

What carries the argument

The central object is the all-at-once discrete system $\mathbf{J}\mathbf{s}=\mathbf{f}$ from a stabilised continuous Galerkin discretisation with time as a third coordinate and artificial time-direction diffusion $\hat{k}_{\mathrm{ad}}=\tfrac12 C\Delta t$. The solver is FGMRES preconditioned by a space-time multigrid V-cycle. The hierarchy follows a semi-coarsening rule: compute $\lambda_{\mathrm{eff},l-1}=D_{\mathrm{eff}}\Delta t_{l-1}/\Delta x_{l-1}^2$; if below $0.5$, double $\Delta t$ (coarsen in time), else double $\Delta x$ (coarsen in space). This keeps cheap pointwise-style smoothers effective on the anisotropic parabolic operator, which is what makes the all-at-once solve fast enoug

What would settle it

Run the comparison problem (Example 1) with the reference time-stepping solver at the full 1280 time steps and 100 or more design iterations, with enough memory and identical tolerances, and compare wall-clock time at 120 and 400 nodes. If the ratio of space-time to time-stepping time is not close to the quoted 25x and 52x, the extrapolated speed-up was the artifact. Separately, a sweep of the threshold $\lambda_{\mathrm{crit}}$ for the CG-STFE discretisation would test whether the semi-coarsening rule is transferable; poor convergence at $\lambda_{\mathrm{crit}}=0.5$ would weaken the method's

Watch

Extended reading notes

Core claim

Central claim: a stabilised continuous Galerkin space-time finite element method, solved all-at-once by a Krylov solver preconditioned with a semi-coarsened space-time multigrid, cuts time-to-solution for transient thermal topology optimisation by over an order of magnitude. Evidence: 52.1x speed-up over a backward-Euler reference (16.4 s vs 855 s), 4.2 billion DOFs solved in ~17 minutes, near-linear scaling from 8 to 400 nodes. Semi-coarsening is load-bearing: state iterations fall 9.7 to 5.6, adjoint 55.6 to 9.4. Time-varying designs are demonstrated, with the authors noting energy conservation is not yet enforced.

Load-bearing premise

The headline speed-ups assume that the time-stepping reference cost grows linearly from the measured 10 steps / 10 iterations to 1280 steps / 100 iterations, and that the semi-coarsening threshold chosen for an earlier discretisation remains the right one for the new space-time Galerkin method; if either gives way, the quoted ratios overstate the gain.

Editorial extensions

If this is right

  • A transient thermal optimisation that takes roughly 15 hours with time-stepping is claimed to finish in under an hour on the same class of machine at about 2.4x the core-hours, changing how many design iterations a developer can afford per day.
  • Spatiotemporal resolutions of billions of unknowns (e.g., 1280x1280x2560 elements) become solvable in minutes, bringing time-dependent design closer to the scale of static large-scale topology optimisation.
  • Time-varying design fields, not just time-constant ones, become optimisable, as shown by conductive spirals tracking a moving heat source.
  • The semi-coarsening choice is worth roughly two-fold fewer state iterations and six-fold fewer adjoint iterations than full coarsening on the fine benchmark, making the preconditioner's hierarchy design the practical key to the speed-up.
  • Because the underlying equation is a linear diffusion equation, the authors expect the same machinery to extend to mass diffusion, charge diffusion, and porous flow, where transient optimisation faces the same time-to-solution bottleneck.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • Extension: the authors' own Section 6.1 caveat that time-varying designs do not conserve energy means the morphing-structure results are best read as demonstrations of solver capability, not yet as physically predictive designs; adding the missing $\partial C/\partial t$ term is a natural next step.
  • Extension: the comparison normalizes by wall-clock time, not by energy or monetary cost; if a user's real constraint is core-hours or budget, the optimum operating point may be the 25x-at-4.8x-cost configuration rather than the 52x-at-7.7x-cost one.
  • Extension: the 52x figure depends on a time-stepping baseline that saturates at around 1000 cores because the 2D spatial problem is small; on problems with genuinely large 3D spatial meshes, time-stepping would scale better, so the space-time advantage might shrink or move to different core counts.
  • Extension: a direct extension suggested by the paper's own framing is to tune coarsening strategies specifically for the adjoint equation, which the results show is harder to converge than the state equation; that could cut the dominant cost in optimisation.
Share X Bluesky LinkedIn Reddit HN

Signed reviews

No signed human review yet.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

4 major / 5 minor

Summary. The paper proposes a space-time topology optimization framework for transient thermal conduction. Time is treated as an extra spatial dimension, the governing equation is discretized with a stabilized continuous Galerkin space-time finite element method, and the resulting all-at-once system is solved with FGMRES preconditioned by a parallel space-time multigrid method using semi-coarsening. The framework is implemented on distributed-memory supercomputers and demonstrated on two benchmark problems, including time-constant and time-varying design fields, with up to 4.2 billion DOFs. The central quantitative claim is a speed-up of up to 52.1× over traditional time-stepping, at moderate increases in core-hour cost.

Significance. If the reported performance is representative, this is a significant contribution: it is among the first demonstrations of parallel-in-time multigrid preconditioning inside large-scale transient topology optimization, and it provides measured scalability data on a leadership-class machine. The paper is transparent about many caveats, lists all solver parameters, reports iteration counts and timings for multiple material cases, and includes a clear validation against a prior coarse-mesh result. The reproducibility-oriented details and the honest discussion of limitations (memory, extrapolated baselines, energy conservation for time-varying designs) strengthen the paper. However, the headline speed-up is conditional on an extrapolated and infeasible time-stepping baseline, and the semi-coarsening criterion is justified only by preliminary tests for the new discretization. These points do not invalidate the method, but they must be addressed before the central claims can be taken at face value.

major comments (4)
  1. [Section 4, Section 4.3 (Fig. 9), Section 5.1.2] The headline 52.1× speed-up is based on a time-stepping reference that was not run at the full time horizon. Section 4 states that only 10 time steps and 10 design iterations were executed for time-stepping, and the 855-second reference is obtained by scaling linearly to 1280 time steps. The paper itself notes that a real 1280-step run exceeds single-node memory, so the comparison excludes memory pressure and any checkpointing/extra-node costs that a feasible run would incur. Linear scaling in the number of time steps is asserted, not demonstrated across this range, and per-step cost can grow through adjoint storage and later optimization iterations. Notably, when the authors supply a more realistic 100-iteration estimate in Section 5.1.2, the speed-up drops to 18.6–20.8×. The 52× figure should either be replaced by a measured full-horizon comparison or be explicitly presented only as a
  2. [Section 3.2.1, Algorithm 1] The multigrid convergence and all scaling results rely on the semi-coarsening criterion (D_eff, λ_eff, λ_crit=0.5), but the manuscript reports only that the formulas were validated for a finite-element-in-space/backward-Euler discretization in prior work [69] and that 'preliminary tests' indicate they work for the CG-STFE discretization. This is a load-bearing assumption: the reported iteration counts in Tables 3 and 5, and therefore the timing comparisons, depend on the chosen coarsening path. The paper should provide quantitative evidence for the CG-STFE case, e.g., convergence factors for representative meshes and material contrasts, or a sensitivity study with respect to λ_crit.
  3. [Section 4.1, Section 5.1.2, Figure 21] The scaling and speed-up comparisons in Section 4 are performed with only 10 design iterations. Section 5.1.2 and Figure 21 show that the number of linear iterations increases substantially later in the optimization, especially for the adjoint solve and for high-contrast designs. Therefore, the Section 4 speed-ups do not directly translate to a full optimization run. The authors acknowledge this, but the abstract and highlights nevertheless state the 52× figure without this qualifier. I recommend reporting the full-optimization timings as the primary comparison and clearly labelling the 10-iteration numbers as a solver-level scaling study.
  4. [Section 5.2.2 and Section 6.1] For the time-varying design examples, the paper states that energy conservation is not ensured because the time derivative of the volumetric capacity is omitted, and that this likely explains the non-physical temperature behaviour in Example 2C. Since time-varying designs are presented as a full capability of the proposed framework, this limitation should be addressed more prominently in the abstract and results: either implement the missing capacity-derivative term, or explicitly restrict the claims for time-varying designs to 'illustrative' rather than physically validated. At minimum, the potential impact on the optimized designs (Figs. 17–20) should be discussed in the main text, not only in the limitations section.
minor comments (5)
  1. [Figure 18] The caption refers to 'Example 2A', but the surrounding text (Section 5.2.2) describes Example 2B with a time-varying design. The caption should be corrected.
  2. [Section 3.1.1, Eq. (21)] The artificial diffusion coefficient is introduced as \hat{k}_{ad} in Eq. (20) but the notation in Eq. (21) and surrounding text is not fully consistent. Please define the symbol once and use it uniformly. Also, the text contains typographical artifacts such as 'P ´eclet' and 'di ffusion'.
  3. [References] Reference [65] contains a typo in the title ('fro' should be 'for'). Please also check the rendering of accented characters throughout the reference list.
  4. [Abstract and Highlights] The abstract and highlights state 'up to 52× speed-up' without the caveats that Section 4 itself acknowledges. Consider adding a qualifier such as 'projected' or 'for a 10-iteration comparison' so that the summary matches the body's more cautious statements.
  5. [Section 4.1 and Figure 7] The unusual sub-node scaling and the performance drops at 140/160 nodes are left unexplained. Even a brief discussion of possible partitioning/load-balancing effects would help the reader interpret the scaling curve.

Circularity Check

0 steps flagged · score 1.0 of 10

No significant circularity: the headline speed-up is an empirically measured comparison, and the self-cited semi-coarsening strategy is additionally validated in-paper against full coarsening.

full rationale

The paper's central claim is a timing comparison: a 16.4 s space-time solve on 400 nodes versus an 855 s time-stepping reference (Section 4.3). The reference is extrapolated from a 10-time-step, 10-iteration run to 1280 time steps using an explicitly stated linear-scaling assumption, and the paper repeatedly cautions that 'the speed-up estimates should be taken with some uncertainty'. This is a robustness/fairness concern about the baseline, not a definitional identity: no equation defines the speed-up in terms of the extrapolated baseline, and the space-time runtime itself is measured. The mathematical derivation (weak form Eq. 19, discretized system Eq. 22, adjoint system Eq. 38) is self-contained and independent of the results. The semi-coarsening strategy is taken from the authors' prior work [69], but the paper does not rely solely on that citation: Section 5.1.2 compares semi-coarsening to full coarsening within the paper (5.6 vs 9.7 state iterations and 9.4 vs 55.6 adjoint iterations), providing independent empirical support for the load-bearing solver choice. The setting λcrit=0.5 is stated as a practical observed choice rather than fitted to the headline result. Self-citations appear, but they are not the basis for the central quantitative claim. No fitted parameter is renamed as a prediction, and no result is equivalent to its input by construction. Therefore the paper does not exhibit circularity; the main risks lie in baseline extrapolation and limited design iterations, which are validity threats, not circular reasoning.

Assumptions & free parameters 5 free parameters · 4 assumptions · 0 invented entities

No new physical entities are introduced; the space-time domain is a mathematical reformulation. The free parameters are mostly solver and optimization choices, with lambda_crit and the semi-coarsening indicator being the least externally grounded. The energy-conservation assumption for time-varying designs is acknowledged by the authors as a known weakness.

free parameters (5)
  • lambda_crit = 0.5
    User-defined threshold in Algorithm 1 that selects semi-coarsening in space vs time; authors state it was observed to work decently in practice (Section 3.2.1).
  • SIMP exponents (pk, pc) = pk=3, pc=2
    Interpolation exponents for conductivity and capacity; adopted from Appel and Alexandersen [65] to enable comparison.
  • Projection sharpness beta = 32
    Heaviside projection parameter; chosen to encourage binary designs (Section 3.3.2).
  • p-norm exponent P = 20
    Objective p-norm exponent set to remain consistent with previous work (Section 3.3.1).
  • Filter radii (rx, rt) = rx=2.4 dx, rt=2.4 dt (default); rt=0.3 for Examples 2B-C
    PDE filter radii; minimally stable values by default, increased for time-varying designs to avoid fast oscillations.
assumptions (4)
  • domain assumption Artificial diffusion k_ad = 0.5 * C * Delta t stabilizes the CG space-time formulation.
    Stabilization makes the scheme first-order accurate in time; used throughout without convergence analysis (Section 3.1.1).
  • ad hoc to paper The semi-coarsening indicator lambda_eff computed with Deff is reliable for CG-STFE discretizations.
    Formulas were calibrated in prior work for backward-Euler spatial FE; authors rely on preliminary tests for the present discretization (Section 3.2.1).
  • domain assumption For time-varying design fields, C(xi) * dT/dt without a dC/dt term conserves energy sufficiently.
    Authors state this is an issue: energy conservation is not ensured when capacity changes in time (Section 5.2.2, Limitations).
  • standard math Galerkin projection of matrices gives correct coarse-grid operators.
    Used for multigrid hierarchy, standard but unproved in this setting.

how reviews work

0 comments
Cite this review

Pith. "Pith review of Large-Scale Topology Optimisation of Time-dependent Thermal Conduction Using Space-Time Finite Elements and a Parallel Space-Time Multigrid Preconditioner." pith.science (2026). https://pith.science/paper/A42FLPQF

@misc{pith2026250809589,
  author       = {Pith},
  title        = {Pith review of: Large-Scale Topology Optimisation of Time-dependent Thermal Conduction Using Space-Time Finite Elements and a Parallel Space-Time Multigrid Preconditioner},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/A42FLPQF}},
  note         = {Machine review of arXiv:2508.09589}
}
read the original abstract

This paper presents a novel space-time topology optimisation framework for time-dependent thermal conduction problems, aiming to significantly reduce the time-to-solution. By treating time as an additional spatial dimension, we discretise the governing equations using a stabilised continuous Galerkin space-time finite element method. The resulting large all-at-once system is solved using an iterative Krylov solver preconditioned with a parallel space-time multigrid method employing a semi-coarsening strategy. Implemented in a fully parallel computing framework, the method yields a parallel-in-time method that demonstrates excellent scalability on a distributed-memory supercomputer, solving problems up to 4.2 billion degrees of freedom. Comparative studies show up to 52x speed-up over traditional time-stepping approaches, with only moderate increases in total computational cost in terms of core-hours. The framework is validated on benchmark problems with both time-constant and time-varying designs, and its flexibility is demonstrated through variations in material properties. These results establish the proposed space-time method as a promising approach for large-scale time-dependent topology optimisation in thermal applications.

Figures

Figures reproduced from arXiv: 2508.09589 by the authors.

Figure 1
Figure 1. Two-dimensional design representation showing the areas of conductive material, [PITH_FULL_IMAGE:figures/full_fig_p007_1.png] view at source ↗
Figure 2
Figure 2. (2+1)D space-time design representation showing the areas of conductive material, Πcon, and insulative material, Πins. To couple the design representation to the governing equation, Equation 7, the volumetric heat capacity and thermal conductivity are then coupled to the design field through interpolation functions: C(x) = CSIMP(γ(x)) (12a) ˜k(x) = ˜kSIMP(γ(x)) (12b) where the functions ˜kSIMP and CSIMP are defined … view at source ↗
Figure 3
Figure 3. Sketch of Example 1: square domain with distributed time-dependent heat source and a small heat sink area at the centre of the bottom [PITH_FULL_IMAGE:figures/full_fig_p009_3.png] view at source ↗
Figures from the paper (21 more)
Figure 4
Figure 4. Figure 4: Sketch of Example 2: square domain with a moving heat source and cold walls around the entire outer boundary. [PITH_FULL_IMAGE:figures/full_fig_p010_4.png]
Figure 5
Figure 5. Figure 5: Illustration of: (a-b) the two semi-coarsening operations available in the semi-coarsening strategy defined in Algorithm 1; (c) suboptimal [PITH_FULL_IMAGE:figures/full_fig_p013_5.png]
Figure 6
Figure 6. Figure 6: Relative speed-up of the time-stepping approach for Example 1, as a function of number of cores on: (a) a single node; (b) multiple [PITH_FULL_IMAGE:figures/full_fig_p017_6.png]
Figure 7
Figure 7. Figure 7: Relative speed-up of the space-time approach for Example 1, as a function of: (a) number of cores on 8 nodes; (b) number of full nodes [PITH_FULL_IMAGE:figures/full_fig_p018_7.png]
Figure 8
Figure 8. Figure 8: Computational time-to-solution, as a function of number of cores for both methods applied to Example 1. [PITH_FULL_IMAGE:figures/full_fig_p019_8.png]
Figure 9
Figure 9. Figure 9: Region 1 shows that the sub-node runs are way too expensive and provide no speed-up, rendering these set [PITH_FULL_IMAGE:figures/full_fig_p019_9.png]
Figure 9
Figure 9. Figure 9: Speed-up for the proposed space-time approach relative to time-stepping on 1 full node, as a function of: (a) relative number of core [PITH_FULL_IMAGE:figures/full_fig_p020_9.png]
Figure 10
Figure 10. Figure 10: Optimised design field for Example 1A with problem settings defined by Appel and Alexandersen [65] and a bounding box showing the [PITH_FULL_IMAGE:figures/full_fig_p021_10.png]
Figure 11
Figure 11. Figure 11: Optimised design for Example 1B using a 640 [PITH_FULL_IMAGE:figures/full_fig_p022_11.png]
Figure 12
Figure 12. Figure 12: Time slices of the space-time domain to illustrate the oscillatory temperature history for Example 1B. The colours denote the temperature [PITH_FULL_IMAGE:figures/full_fig_p022_12.png]
Figure 13
Figure 13. Figure 13: Optimised design for Example 1C with higher conductivity shown in: (a) a two-dimensional spatial representation with a bounding box [PITH_FULL_IMAGE:figures/full_fig_p023_13.png]
Figure 14
Figure 14. Figure 14: Optimised design for Example 1D with higher volumetric capacity shown in: (a) a two-dimensional spatial representation with a [PITH_FULL_IMAGE:figures/full_fig_p024_14.png]
Figure 15
Figure 15. Figure 15: Temperature history for the higher volumetric capacity case, Example 1D: (a) the full space-time domain; (b-c) time slices at two peaks [PITH_FULL_IMAGE:figures/full_fig_p024_15.png]
Figure 16
Figure 16. Figure 16: Optimised design for Example 2A: (a) two-dimensional spatial representation of design field with a bounding box showing the edges [PITH_FULL_IMAGE:figures/full_fig_p026_16.png]
Figure 17
Figure 17. Figure 17: Optimised time-varying space-time design for Example 2B, with a black bounding box showing the design domain and coloured [PITH_FULL_IMAGE:figures/full_fig_p027_17.png]
Figure 18
Figure 18. Figure 18: Time slices of the space-time domain to illustrate the movement of the conductive material for Example 2A. The colours show the [PITH_FULL_IMAGE:figures/full_fig_p027_18.png]
Figure 19
Figure 19. Figure 19: Optimised time-varying space-time design for Example 2C, with a black bounding box showing the design domain and coloured [PITH_FULL_IMAGE:figures/full_fig_p028_19.png]
Figure 20
Figure 20. Figure 20: Time slices of the space-time domain to illustrate the movement of the conductive material for Example 2C with a high volumetric [PITH_FULL_IMAGE:figures/full_fig_p028_20.png]
Figure 21
Figure 21. Figure 21: History of the number of state and adjoint linear iterations for the two di [PITH_FULL_IMAGE:figures/full_fig_p030_21.png]
Figure 22
Figure 22. Figure 22: Optimised time-varying space-time design for Example 2E, with a black bounding box showing the design domain and coloured [PITH_FULL_IMAGE:figures/full_fig_p031_22.png]
Figure 23
Figure 23. Figure 23: Time slice at t = 2.75 of the thresholded space-time design to show the detail level for Example 2D: (a) the whole time slice showing only the design; (b) zoomed-in view; (c) further zoomed-in view showing the finite elements. For (a-b) the colours show the temperatur…

Discussion (0). Continue with ORCID to comment.

Reference graph

Works this paper leans on

103 extracted references · 56 canonical work pages

  1. [69]

    Space-Time Multigrid Methods Suitable for Topology Optimisation of Transient Heat Conduction

    M. Appel, J. Alexandersen, Space-time multigrid methods suitable for topology optimisation of transient heat conduction, Preprint available on arXiv:2505.10168 (2025)

  2. [1]

    M. P. Bendsøe, N. Kikuchi, Generating optimal topologies in structural design using a homogenization method, Computer Methods in Applied Mechanics and Engineering 71 (1988) 197–224. doi:https://doi.org/10.1016/0045-7825(88)90086-2

  3. [2]

    M. P. Bendsøe, O. Sigmund, Topology Optimization: Theory, Methods, and Applications, 2 ed., Springer-Verlag Berlin Heidelberg, 2004. doi:10.1007/978-3-662-05086-6

  4. [3]

    J. D. Deaton, R. V . Grandhi, A survey of structural and multidisciplinary continuum topology optimization: post 2000, Structural and Multidisciplinary Optimization 49 (2014) 1–38. doi:10.1007/s00158-013-0956-z

  5. [4]

    G. M. Amdahl, Validity of the single processor approach to achieving large scale computing capabilities, in: Proceedings of the April 18-20, 1967, Spring Joint Computer Conference, AFIPS ’67 (Spring), Association for Computing Machinery, 1967, p. 483–485. doi:10.1145/1465482.1465560

  6. [5]

    Mukherjee, D

    S. Mukherjee, D. Lu, B. Raghavan, P. Breitkopf, S. Dutta, M. Xiao, W. Zhang, Accelerating large-scale topology optimization: state-of-the- art and challenges, Archives of Computational Methods in Engineering (2021) 1–23. doi:10.1007/s11831-021-09544-3

  7. [6]

    Borrvall, J

    T. Borrvall, J. Petersson, Large-scale topology optimization in 3d using parallel computing, Computer Methods in Applied Mechanics and Engineering 190 (2001) 6201–6229. doi:10.1016/S0045-7825(01)00216-X

  8. [7]

    Evgrafov, C

    A. Evgrafov, C. J. Rupp, K. Maute, M. L. Dunn, Large-scale parallel topology optimization using a dual-primal substructuring solver, Structural and Multidisciplinary Optimization 36 (2008) 329–345. doi:10.1007/s00158-007-0190-7. 32

Show all 103 references
  1. [8]

    N. Aage, B. S. Lazarov, Parallel framework for topology optimization using the method of moving asymptotes, Structural and Multidisci- plinary Optimization 47 (2013) 493–505. doi:10.1007/s00158-012-0869-2

  2. [9]

    O. Amir, N. Aage, B. S. Lazarov, On multigrid-CG for e fficient topology optimization, Structural and Multidisciplinary Optimization 49 (2014) 815–829. doi:10.1007/s00158-013-1015-5

  3. [10]

    N. Aage, E. Andreassen, B. S. Lazarov, Topology optimization using PETSc: An easy-to-use, fully parallel, open source topology optimiza- tion framework, Structural and Multidisciplinary Optimization 51 (2015) 565–572. doi:10.1007/s00158-014-1157-0

  4. [11]

    Balay, S

    S. Balay, S. Abhyankar, M. F. Adams, S. Benson, J. Brown, P. Brune, K. Buschelman, E. Constantinescu, L. Dalcin, A. Dener, V . Ei- jkhout, J. Faibussowitsch, W. D. Gropp, V . Hapla, T. Isaac, P. Jolivet, D. Karpeev, D. Kaushik, M. G. Knepley, F. Kong, S. Kruger, D. A. May, L. ...

  5. [12]

    N. Aage, E. Andreassen, B. S. Lazarov, O. Sigmund, Giga-voxel computational morphogenesis for structural design, Nature 550 (2017) 84–86. doi:10.1038/nature23911

  6. [13]

    Baandrup, O

    M. Baandrup, O. Sigmund, H. Polk, N. Aage, Closing the gap towards super-long suspension bridges using computational morphogenesis, Nature Communications 11 (2020) 2735. doi:10.1038/s41467-020-16599-6

  7. [14]

    Alexandersen, O

    J. Alexandersen, O. Sigmund, N. Aage, Large scale three-dimensional topology optimisation of heat sinks cooled by natural convection, International Journal of Heat and Mass Transfer 100 (2016) 876–891. doi:10.1016/j.ijheatmasstransfer.2016.05.013

  8. [15]

    L. C. Høghøj, D. R. Nørhave, J. Alexandersen, O. Sigmund, C. S. Andreasen, Topology optimization of two fluid heat exchangers, Interna- tional Journal of Heat and Mass Transfer 163 (2020) 120543. doi:https://doi.org/10.1016/j.ijheatmasstransfer.2020.120543

  9. [16]

    Rogi ´e, C

    B. Rogi ´e, C. S. Andreasen, Design complexity tradeo ffs in topology optimization of forced convection laminar flow heat sinks, Structural and Multidisciplinary Optimization 66 (2022) 6. doi:10.1007/s00158-022-03449-w

  10. [17]

    Y . Zhou, C. Ye, Y . Liu, S. Fu, E. T. Chung, A robust solver for large-scale heat transfer topology optimization, 2025. URL: https://arxiv.org/abs/2410.06850. arXiv:2410.06850

  11. [18]

    Herrero-P ´erez, S

    D. Herrero-P ´erez, S. G. Pic ´o-Vicente, A parallel geometric multigrid method for adaptive topology optimization, Structural and Multidis- ciplinary Optimization 66 (2023) 225. doi:10.1007/s00158-023-03675-w

  12. [19]

    S. Luo, F. Yang, Y . Wang, An e fficient isogeometric topology optimization based on the adaptive damped geometric multigrid method, Advances in Engineering Software 196 (2024) 103712. doi:10.1016/j.advengsoft.2024.103712

  13. [20]

    S. Min, N. Kikuchi, Y . C. Park, S. Kim, S. Chang, Optimal topology design of structures under dynamic loads, Structural optimization 17 (1999) 208–218. doi:10.1007/BF01195945

  14. [21]

    Q. Li, G. Steven, Y . M. Xie, Thermoelastic topology optimization for problems with varying temperature fields, Journal of Thermal Stresses 24 (2001) 347–366. doi:10.1080/01495730151078153

  15. [22]

    Zhuang, Z

    C. Zhuang, Z. Xiong, H. Ding, Topology optimization of the transient heat conduction problem on a triangular mesh, Numerical Heat Transfer, Part B: Fundamentals 64 (2013) 239–262. doi:10.1080/10407790.2013.791785

  16. [23]

    Zhuang, Z

    C. Zhuang, Z. Xiong, Temperature-constrained topology optimization of transient heat conduction problems, Numerical Heat Transfer, Part B: Fundamentals 68 (2015) 366–385. doi:10.1080/10407790.2015.1033306

  17. [24]

    S. Wu, Y . Zhang, S. Liu, Topology optimization for minimizing the maximum temperature of transient heat conduction structure, Structural and Multidisciplinary Optimization 60 (2019) 69–82. doi:10.1007/s00158-019-02196-9

  18. [25]

    T. Zeng, H. Wang, M. Yang, J. Alexandersen, Topology optimization of heat sinks for instantaneous chip cooling using a transient pseudo-3d thermofluid model, International Journal of Heat and Mass Transfer 154 (2020) 119681. doi:10.1016/j.ijheatmasstransfer.2020.119681

  19. [26]

    Srinivas, G

    V . Srinivas, G. Ananthasuresh, Analysis and topology optimization of heat sinks with a phase- change material on COMSOL multiphysics platform, in: Proceedings of the COMSOL Users Conference 2006 Bangalore, 2006. URL: https://www.researchgate.net/publication/267679913

  20. [27]

    Pizzolato, A

    A. Pizzolato, A. Sharma, K. Maute, A. Sciacovelli, V . Verda, Topology optimization for heat transfer enhancement in latent heat thermal energy storage, International Journal of Heat and Mass Transfer 113 (2017) 875–888. doi:10.1016/j.ijheatmasstransfer.2017.05.098

  21. [28]

    Lundgaard, K

    C. Lundgaard, K. Engelbrecht, O. Sigmund, A density-based topology optimization methodology for thermal energy storage systems, Structural and Multidisciplinary Optimization 60 (2019) 2189–2204. doi:10.1007/s00158-019-02375-8

  22. [29]

    Q. Yao, C. Zhao, Y . Zhao, H. Wang, W. Li, Topology optimization for heat transfer enhancement in latent heat storage, International Journal of Thermal Sciences 159 (2021) 106578. doi:10.1016/j.ijthermalsci.2020.106578

  23. [30]

    M. B. M. Christensen, J. Alexandersen, Topology optimisation of heat sinks embedded with phase-change material for minimising temper- ature oscillations, 2023. URL: https://hal.science/hal-04185641, working paper or preprint

  24. [31]

    Y . Li, K. Saitou, N. Kikuchi, Topology optimization of thermally actuated compliant mechanisms considering time-transient e ffect, Finite Elements in Analysis and Design 40 (2004) 1317–1331. doi:10.1016/j.finel.2003.05.002

  25. [32]

    Y . Guo, S. Cheng, Y . Wang, X. Lai, L. Chen, Topology optimization for transient thermoelastic structures under time-dependent loads, Engineering with Computers 40 (2024) 1677–1693. doi:10.1007/s00366-023-01878-9

  26. [33]

    Michaleris, D

    P. Michaleris, D. A. Tortorelli, C. A. Vidal, Tangent operators and design sensitivity formulations for transient non-linear coupled problems with applications to elastoplasticity, International Journal for Numerical Methods in Engineering 37 (1994) 2471–2499. doi:10.1002/nme....

  27. [34]

    J. Dahl, J. S. Jensen, O. Sigmund, Topology optimization for transient wave propagation problems in one dimension, Structural and Multidisciplinary Optimization 36 (2008) 585–595. doi:10.1007/s00158-007-0192-5

  28. [35]

    Elesin, B

    Y . Elesin, B. S. Lazarov, J. S. Jensen, O. Sigmund, Time domain topology optimization of 3D nanophotonic devices, Photonics and Nanostructures - Fundamentals and Applications 12 (2014) 23–33. doi:https://doi.org/10.1016/j.photonics.2013.07.008

  29. [36]

    Co ffin, K

    P. Co ffin, K. Maute, A level-set method for steady-state and transient natural convection problems, Structural and Multidisciplinary Optimization 53 (2016) 1047–1067. doi:10.1007/s00158-015-1377-y

  30. [37]

    Kristiansen, N

    H. Kristiansen, N. Aage, An open-source framework for large-scale transient topology optimization using petsc, Structural and Multidisci- plinary Optimization 65 (2022) 295. doi:10.1007/s00158-022-03312-y. 33

  31. [38]

    D. S. Makhija, P. S. Beran, Concurrent shape and topology optimization for unsteady conjugate heat transfer, Structural and Multidisci- plinary Optimization 62 (2020) 1275–1297. doi:10.1007/s00158-020-02554-y

  32. [39]

    Griewank, Achieving logarithmic growth of temporal and spatial complexity in reverse automatic di fferentiation 1 (1992) 35–54

    A. Griewank, Achieving logarithmic growth of temporal and spatial complexity in reverse automatic di fferentiation 1 (1992) 35–54

  33. [40]

    Griewank, A

    A. Griewank, A. Walther, Algorithm 799: revolve: an implementation of checkpointing for the reverse or adjoint mode of computational differentiation, ACM Trans. Math. Softw. 26 (2000) 19–45. doi:10.1145/347837.347846

  34. [41]

    A.-S. I. Margetis, E. M. Papoutsis-Kiachagias, K. C. Giannakoglou, Reducing memory requirements of unsteady adjoint by synergistically using check-pointing and compression, International Journal for Numerical Methods in Fluids 95 (2023) 23–43. doi:https://doi.org/10.1002/fld.5136

  35. [42]

    N. K. Yamaleev, B. Diskin, E. J. Nielsen, Local-in-time adjoint-based method for design optimization of unsteady flows, Journal of Computational Physics 229 (2010) 5394–5407. doi:10.1016/j.jcp.2010.03.045

  36. [43]

    C. Chen, K. Yaji, T. Yamada, K. Izui, S. Nishiwaki, Local-in-time adjoint-based topology optimization of unsteady fluid flows using the lattice boltzmann method, Mechanical Engineering Journal 4 (2017) 17–00120–17–00120. doi:10.1299/mej.17-00120

  37. [44]

    K. Yaji, M. Ogino, C. Chen, K. Fujita, Large-scale topology optimization incorporating local-in-time adjoint-based method for unsteady thermal-fluid problem, Structural and Multidisciplinary Optimization 58 (2018) 817–822. doi:10.1007/s00158-018-1922-6

  38. [45]

    M. J. B. Theulings, R. Maas, L. No ¨el, F. van Keulen, M. Langelaar, Reducing time and memory requirements in topology optimization of transient problems, International Journal for Numerical Methods in Engineering 125 (2024) e7461. doi:10.1002/nme.7461

  39. [46]

    J. Hyun, S. Wang, Systematically engineered thermal metastructure for rapid heat dissipation /diffusion by considering the thermal eigen- value, Applied Thermal Engineering 157 (2019) 113487. doi:https://doi.org/10.1016/j.applthermaleng.2019.03.058

  40. [47]

    J. Hyun, H. A. Kim, Level-set topology optimization for e ffective control of transient conductive heat response using eigenvalue, Interna- tional Journal of Heat and Mass Transfer 176 (2021) 121374. doi:10.1016/j.ijheatmasstransfer.2021.121374

  41. [48]

    Onodera, T

    S. Onodera, T. Yamada, A topology optimization method for managing transient thermal and vibration e ffects with eigenvalues and steady- state constraints, International Journal of Heat and Mass Transfer 246 (2025) 127083. doi:10.1016/j.ijheatmasstransfer.2025.127083

  42. [49]

    Isiklar, R

    G. Isiklar, R. E. Christiansen, O. Sigmund, Topology optimization of thermal initial value problems exploiting e fficient harmonic analysis,

  43. [50]

    K. Yan, D. Liu, J. Yan, Topology optimization method for transient heat conduction using the lyapunov equation, International Journal of Heat and Mass Transfer 231 (2024) 125815. doi:10.1016/j.ijheatmasstransfer.2024.125815

  44. [51]

    E. C. Hooijkamp, F. v. Keulen, Topology optimization for linear thermo-mechanical transient problems: Modal reduction and adjoint sensitivities, International Journal for Numerical Methods in Engineering 113 (2018) 1230–1257. doi:10.1002/nme.5635

  45. [52]

    van der Kolk, E

    M. van der Kolk, E. C. Hooijkamp, M. Langelaar, F. van Keulen, Using exact particular solutions and modal reduction in topology optimization of transient thermo-mechanical problems, in: A. Schumacher, T. Vietor, S. Fiebig, K.-U. Bletzinger, K. Maute (Eds.), Advances in Structu...

  46. [53]

    S. Li, J. Yin, X. Jiang, Y . Zhang, H. Wang, A novel reduced basis method for adjoint sensitivity analysis of dynamic topology optimization, Engineering Analysis with Boundary Elements 162 (2024) 403–419. doi:10.1016/j.enganabound.2024.03.001

  47. [54]

    S. Li, J. Yin, Y . Zhang, H. Wang, An online reduced-order method for dynamic sensitivity analysis, Engineering Analysis with Boundary Elements 175 (2025) 106198. doi:10.1016/j.enganabound.2025.106198

  48. [55]

    M. J. Gander, 50 years of time parallel time integration, in: T. Carraro, M. Geiger, S. K ¨orkel, R. Rannacher (Eds.), Multiple Shooting and Time Domain Decomposition Methods, Springer International Publishing, Cham, 2015, pp. 69–113

  49. [56]

    B. W. Ong, J. B. Schroder, Applications of time parallelization, Computing and Visualization in Science 23 (2020) 11. doi:10.1007/s00791- 020-00331-4

  50. [57]

    Lions, Y

    J.-L. Lions, Y . Maday, G. Turinici, R ´esolution d’edp par un sch´ema en temps parar´eel, Comptes Rendus de l’Acad ´emie des Sciences - Se- ries I - Mathematics 332 (2001) 661–668. URL: https://www.sciencedirect.com/science/article/pii/S0764444200017936. doi:https://doi.org/1...

  51. [58]

    Friedho ff, R

    S. Friedho ff, R. D. Falgout, T. Kolev, S. MacLachlan, J. B. Schroder, A multigrid-in-time algorithm for solving evolution equations in parallel, Technical Report, Lawrence Livermore National Lab.(LLNL), Livermore, CA (United States), 2012

  52. [59]

    D. E. Womble, A time-stepping algorithm for parallel computers, SIAM Journal on Scientific and Statistical Computing 11 (1990) 824–837. URL: https://doi.org/10.1137/0911049. doi:10.1137/0911049

  53. [60]

    Emmett, M

    M. Emmett, M. Minion, Toward an e fficient parallel in time method for partial di fferential equations, Communications in Applied Mathe- matics and Computational Science 7 (2012) 105–132

  54. [61]

    Hahne, B

    J. Hahne, B. Polenz, I. Kulchytska-Ruchka, S. Friedho ff, S. Ulbrich, S. Sch ¨ops, Parallel-in-time optimization of induction motors, Journal of Mathematics in Industry 13 (2023) 6

  55. [62]

    X. Du, M. Sarkis, C. E. Schaerer, D. B. Szyld, Inexact and truncated parareal-in-time krylov subspace methods for parabolic optimal control problems, Electronic Transactions on Numerical Analysis 40 (2013) 36–57

  56. [63]

    G ¨otschel, M

    S. G ¨otschel, M. L. Minion, Parallel-in-time for parabolic optimal control problems using pfasst, in: P. E. Bjørstad, S. C. Brenner, L. Halpern, H. H. Kim, R. Kornhuber, T. Rahman, O. B. Widlund (Eds.), Domain Decomposition Methods in Science and Engineering XXIV , Springer I...

  57. [64]

    N. R. G. S. G ¨unther, J. B. Schroder, A non-intrusive parallel-in-time approach for simultaneous optimization with unsteady pdes, Optimiza- tion Methods and Software 34 (2019) 1306–1321. doi:10.1080/10556788.2018.1504050

  58. [65]

    Appel, J

    M. Appel, J. Alexandersen, One-shot Parareal approach fro topology optimisation of transient heat flow, Preprint available on arXiv:2411.19030 (2024)

  59. [66]

    Hackbusch, Parabolic multi-grid methods, in: R

    W. Hackbusch, Parabolic multi-grid methods, in: R. Glowinski, J.-L. Lions (Eds.), Computing methods in applied sciences and engineering VI, Elsevier science publishers B.V ., 1983, pp. 189–197

  60. [67]

    R. D. Falgout, S. Friedho ff, T. V . Kolev, S. P. MacLachlan, J. B. Schroder, S. Vandewalle, Multigrid methods with space–time concurrency, Computing and Visualization in Science 18 (2017) 123–143. doi:10.1007/s00791-017-0283-9

  61. [68]

    Horton, S

    G. Horton, S. Vandewalle, A space-time multigrid method for parabolic partial differential equations, SIAM Journal on Scientific Computing 16 (1995) 848–864. 34

  62. [70]

    Alexandersen, Towards fast topology optimisation of transient problems: parallel space-time multigrid, 2023

    J. Alexandersen, Towards fast topology optimisation of transient problems: parallel space-time multigrid, 2023. URL: https://easychair.org/smart-program/CM2023/2023-04-18.html#talk:214721. doi:10.13140 /RG.2.2.12680.33283, 21st Copper Mountain Conference on Multigrid Methods

  63. [71]

    Alexandersen, M

    J. Alexandersen, M. Appel, Towards fast topology optimisation of transient heat conduction using parallel space-time methods, 2025. doi:10.13140/RG.2.2.26102.10563, 16th World Congress on Structural and Multidisciplinary Optimization

  64. [72]

    Sigmund, K

    O. Sigmund, K. Maute, Topology optimization approaches, Structural and Multidisciplinary Optimization 48 (2013) 1031–1055. doi:10.1007/s00158-013-0978-6

  65. [73]

    J. S. Jensen, Space–time topology optimization for one-dimensional wave propagation, Computer Methods in Applied Mechanics and Engineering 198 (2009) 705–715. doi:10.1016/j.cma.2008.10.008

  66. [74]

    Jensen, Optimization of space-time material layout for 1d wave propagation with varying mass and sti ffness parameters, volume 39, Sciendo, 2010, pp

    J. Jensen, Optimization of space-time material layout for 1d wave propagation with varying mass and sti ffness parameters, volume 39, Sciendo, 2010, pp. 599–614. Workshop On Optimization with PDE Constraints ; Conference date: 01-01-2008 Through 01-01-2008

  67. [75]

    W. Wang, D. Munro, C. C. L. Wang, F. van Keulen, J. Wu, Space-time topology optimization for additive manufacturing, Structural and Multidisciplinary Optimization 61 (2020) 1–18. doi:10.1007/s00158-019-02420-6

  68. [76]

    B. L. Hulme, One-step piecewise polynomial galerkin methods for initial value problems, Mathematics of Computation 26 (1972) 415–426. doi:10.2307/2005168

  69. [77]

    Winther, A stable finite element method for initial-boundary value problems for first-order hyperbolic systems, Mathematics of Compu- tation - Math

    R. Winther, A stable finite element method for initial-boundary value problems for first-order hyperbolic systems, Mathematics of Compu- tation - Math. Comput. 36 (1981) 65–65. doi:10.1090/S0025-5718-1981-0595042-6

  70. [78]

    A. K. Aziz, P. Monk, Continuous finite elements in space and time for the heat equation, Mathematics of Computation 52 (1989) 255–274

  71. [79]

    G. M. Hulbert, T. J. Hughes, Space-time finite element methods for second-order hyperbolic equations, Computer Methods in Applied Mechanics and Engineering 84 (1990) 327–348. doi:10.1016/0045-7825(90)90082-W

  72. [80]

    Steinbach, H

    O. Steinbach, H. Yang, 7. Space-time finite element methods for parabolic evolution equations: discretization, a posteriori error estimation, adaptivity and solution, De Gruyter, Berlin, Boston, 2019, pp. 207–248. doi:10.1515/9783110548488-007

  73. [81]

    Langer, M

    U. Langer, M. Neum ¨uller, A. Schafelner, Space-Time Finite Element Methods for Parabolic Evolution Problems with Variable Coefficients, Springer International Publishing, Cham, 2019, pp. 247–275. doi:10.1007/978-3-030-14244-5 13

  74. [82]

    von Danwitz, I

    M. von Danwitz, I. V oulis, N. Hosters, M. Behr, Time-continuous and time-discontinuous space-time finite elements for advection-diffusion problems, International Journal for Numerical Methods in Engineering 124 (2023) 3117–3144. doi:10.1002/nme.7241

  75. [83]

    A. N. Brooks, T. J. Hughes, Streamline upwind/petrov-galerkin formulations for convection dominated flows with particular emphasis on the incompressible navier-stokes equations, Computer Methods in Applied Mechanics and Engineering 32 (1982) 199–259. doi:10.1016/0045- 7825(82)90071-8

  76. [84]

    Strang, G

    G. Strang, G. Fix, An Analysis of the Finite Element Method, Prentice-Hall, 1973

  77. [85]

    T. J. Hughes, The finite element method: linear static and dynamic finite element analysis, Prentice-Hall, 1987

  78. [86]

    Hansbo, A crank–nicolson type space–time finite element method for computing on moving meshes, Journal of Computational Physics 159 (2000) 274–289

    P. Hansbo, A crank–nicolson type space–time finite element method for computing on moving meshes, Journal of Computational Physics 159 (2000) 274–289. doi:10.1006/jcph.2000.6436

  79. [87]

    Saad, A flexible inner-outer preconditioned gmres algorithm, SIAM Journal on Scientific Computing 14 (1993) 461–469

    Y . Saad, A flexible inner-outer preconditioned gmres algorithm, SIAM Journal on Scientific Computing 14 (1993) 461–469

  80. [88]

    Y . Saad, M. H. Schultz, Gmres: A generalized minimal residual algorithm for solving nonsymmetric linear systems, SIAM Journal on Scientific and Statistical Computing 7 (1986) 856–869. doi:10.1137/0907058

  81. [89]

    M. J. Gander, M. Neum ¨uller, Analysis of a new space-time parallel multigrid algorithm for parabolic problems, SIAM Journal on Scientific Computing 38 (2016) A2173–A2208. URL: https://doi.org/10.1137/15M1046605. doi:10.1137/15M1046605

  82. [90]

    S. R. Franco, F. J. Gaspar, M. A. Villela Pinto, C. Rodrigo, Multigrid method based on a space-time approach with standard coarsening for parabolic problems, Applied Mathematics and Computation 317 (2018) 25–34. URL: https://www.sciencedirect.com/science/article/pii/S009630031...

  83. [91]

    B. S. Lazarov, O. Sigmund, Filters in topology optimization based on helmholtz-type di fferential equations, International Journal for Numerical Methods in Engineering 86 (2011) 765–781. doi:10.1002/nme.3072

  84. [92]

    B. Wang, Y . Zhou, K. Tian, G. Wang, Novel implementation of extrusion constraint in topology optimization by helmholtz-type anisotropic filter, Structural and Multidisciplinary Optimization 62 (2020) 2091–2100. doi:10.1007/s00158-020-02597-1

  85. [93]

    J. K. Guest, J. H. Pr ´evost, T. Belytschko, Achieving minimum length scale in topology optimization using nodal design variables and projection functions, International journal for numerical methods in engineering 61 (2004) 238–254

  86. [94]

    F. Wang, B. S. Lazarov, O. Sigmund, On projection methods, convergence and robust formulations in topology optimization, Structural and multidisciplinary optimization 43 (2011) 767–784

  87. [95]

    Svanberg, The method of moving asymptotes—a new method for structural optimization, International Journal for Numeri- cal Methods in Engineering 24 (1987) 359–373

    K. Svanberg, The method of moving asymptotes—a new method for structural optimization, International Journal for Numeri- cal Methods in Engineering 24 (1987) 359–373. URL: https://onlinelibrary.wiley.com/doi/abs/10.1002/nme.1620240207. doi:https://doi.org/10.1002/nme.1620240207

  88. [96]

    J. K. Guest, A. Asadpoure, S.-H. Ha, Eliminating beta-continuation from heaviside projection and density filter algorithms, Structural and Multidisciplinary Optimization 44 (2011) 443–453

  89. [97]

    Accessed: 2025-07-15

    Lumi-c specifications, https://docs.lumi-supercomputer.eu/hardware/lumic/, 2025. Accessed: 2025-07-15

  90. [98]

    S. Yan, F. Wang, O. Sigmund, On the non-optimality of tree structures for heat conduction, International Journal of Heat and Mass Transfer 122 (2018) 660–680. doi:10.1016/j.ijheatmasstransfer.2018.01.114

  91. [99]

    B. S. Lazarov, Topology optimization using multiscale finite element method for high-contrast media, in: I. Lirkov, S. Margenov, J. Wa ´sniewski (Eds.), Large-Scale Scientific Computing, Springer Berlin Heidelberg, Berlin, Heidelberg, 2014, pp. 339–346. doi:10.1007/978-3-662-4...

  92. [100]

    Alexandersen, B

    J. Alexandersen, B. S. Lazarov, Topology optimisation of manufacturable microstructural details without length scale separation using a spectral coarse basis preconditioner, Computer Methods in Applied Mechanics and Engineering 290 (2015) 156–182. doi:0.1016/j.cma.2015.02.028. 35

  93. [101]

    G ¨otschel, M

    S. G ¨otschel, M. Minion, D. Ruprecht, R. Speck, Twelve ways to fool the masses when giving parallel-in-time results, in: B. Ong, J. Schroder, J. Shipton, S. Friedhoff (Eds.), Parallel-in-Time Integration Methods, Springer International Publishing, Cham, 2021, pp. 81–94

  94. [102]

    G. E. Myers, The critical time step for finite-element solutions to two-dimensional heat-conduction transients, Journal of Heat Transfer 100 (1978) 120–127. doi:10.1115/1.3450485. 36

  95. [2024]

    URL: https://www.researchsquare.com/article/rs-3984636/v1, preprint

Pith tools

Reviewed August 5, 2026 · model on record in the stance chip above.