Organizations: Key Laboratory for Satellite Digitalization Technology, Innovation Academy for Microsatellites, Chinese Academy of Sciences, Shanghai, China · School of Aeronautics and Astronautics, Shanghai Jiao Tong University, Shanghai, China
Spacecraft thermal design requires repeated evaluation of how variations in the number and spatial arrangement of heat-generating components and in thermal boundary conditions affect the temperature field. High-fidelity numerical simulations are computationally expensive and therefore difficult to use for large-scale design screening. Although surrogate models can accelerate temperature-field prediction, existing approaches generally encode each complete configuration as a whole and do not explicitly exploit the reusability of local physical constituents across configurations, which limits their accuracy for component counts and combinations not covered during training. To address this issue, we propose the Tree-Structured Factor Composition Network (TFCN), which decomposes complex spacecraft thermal configurations into reusable local physical factors and employs a tree-structured composition module to learn the global temperature-field response associated with different factor combinations. TFCN is evaluated on two-dimensional steady-state spacecraft thermal-analysis cases with prescribed-temperature and radiative-flux boundary conditions. The model is trained exclusively on configurations containing no more than 15 heat-generating components and evaluated on unseen configurations containing 16-25 components. For the prescribed-temperature and radiative-flux cases, TFCN achieves component-count out-of-distribution RMSE values of 4.21 K and 18.62 K, respectively, representing reductions of 65.6% and 33.6% relative to the strongest baseline. These results demonstrate that TFCN improves the reliability of temperature-field prediction under variations in component count and provides an efficient surrogate for rapid spacecraft thermal-design evaluation and large-scale configuration screening.
Figures & tables
Category
Method
Phys. loss constraint
Variable-count feature input
Object/subblock encoding
Shared recursive composition
Physical consistency constraints
PINN (2019) [ 11 ]
✓
×
×
×
PI-ML (2023) [ 7 ]
✓
×
×
×
PI-DeepONet (2024) [ 12 ]
✓
×
×
×
DSSL (2026) [ 8 ]
✓
×
×
×
Spatial/set representation
DeepSets (2017) [ 13 ]
×
✓
✓
×
GINO (2023) [ 14 ]
×
✓
✓
×
Table 1: Literature-level feature matrix for related physical-field surrogate methods.
Figure 1: From a componentized spacecraft layout to the two-dimensional HSL-TFP problem. The underlying problem follows the general heat-source-layout benchmark of Chen et al. [ 21 ] , and its spacecraft-oriented extension follows our previous work [ 8 ] .
Figure 2: Automated data-generation pipeline inherited from our previous work [ 8 ] .
Figure 3: Data construction and evaluation splits.
Figure 4: Overall TFCN framework.
Figure 5: Multi-path latent-space composition.
Dataset
Method
K -ID
K -OOD
RMSE
MAE
RMSE
MAE
Temp-BC
UNet
9.99±0.27
6.83±0.10
46.91±1.56
33.52±1.22
DeepONet
12.94±0.24
9.18±0.12
38.95±1.19
29.13±0.68
GINO
3.09±0.15
2.06±0.04
12.23±0.55
5.42±0.32
TFCN-SP
4.88±0.76
2.97±0.42
15.66±2.00
9.12±2.37
TFCN-TP
1.45±0.13
0.95±0.07
4.21±0.15
2.56±0.09
Table 2: Interpolation and high-component-count extrapolation performance. Values are reported as mean ± standard deviation over five independent runs.
Figure 6: Per- K extrapolation error.
Figure 7: Training coverage and composition depth.
Dataset
Method
K -ID
K -OOD
OOD/ID
RMSE
MAE
RMSE
MAE
Temp-BC
TFCN-SP
4.88
2.97
15.66
9.12
3.209
w/o Locality
4.35
2.53
18.49
10.29
4.254
w/o Composition
18.62
11.58
54.03
40.11
2.902
RadFlux-BC
TFCN-SP
10.53
7.32
23.06
15.45
2.190
w/o Locality
10.00
7.12
25.29
15.70
2.529
Table 3: Structural ablation results.
Figure 8: PHATE diagnostic of intermediate-representation geometry.
Figure 9: MMD diagnostic of the ID/OOD latent-distribution discrepancy.
Figure 10: Single-sample intermediate-representation diagnostic during factor composition. Intermediate panels are decoder projections; only the fully composed 15/15 panel is the final full-system temperature prediction and uses the Kelvin scale.
Appendix figures & tables12 assets
Supplementary material from the paper’s appendix.
Appendix
Symbol
Meaning
Ωh
Discrete grid
G
Coordinate condition
C
Heat-source components
B
Boundary segments
F
Factors
fi
Factor representation
Appendix
Table 1: Summary of principal notation used in TFCN.
High-density through-substrate vias (TSVs) enable 2.5D/3D heterogeneous integration but introduce significant signal-integrity and thermal-reliability challenges due to electrical coupling, insertion loss, and self-heating. Conventional full-wave finite-element method (FEM) simulations provide high accuracy but become computationally prohibitive for large design-space exploration. This work presents a scalable electro--thermal modeling and optimization framework that combines physics-informed analytical modeling, graph neural network (GNN) surrogates, and full-wave sign-off validation. A multi-conductor analytical model computes broadband S-parameters and effective anisotropic thermal conductivities of TSV arrays, achieving 5%--10% relative Frobenius error (RFE) across array sizes up to 15×15. A physics-informed GNN surrogate (TSV-PhGNN), trained on analytical data and fine-tuned with HFSS simulations, generalizes to larger arrays with mean RFE below 5% in-distribution. The surrogate is integrated into a multi-objective Pareto optimization framework targeting reflection coefficient, insertion loss, worst-case crosstalk (NEXT/FEXT), and effective thermal conductivity. Millions of TSV configurations can be explored within minutes, enabling exhaustive layout and geometric optimization that would be infeasible using FEM alone. Final designs are validated with Ansys HFSS and Mechanical, showing strong agreement. The proposed framework enables rapid electro--thermal co-design of TSV arrays while reducing per-design evaluation time by more than six orders of magnitude.
Mohamed Gharib, Leonid Popryho, Inna Partin-Vaisband
Department of Electrical and Computer Engineering, University of Illinois Chicago, Chicago, IL 60607, USA
Transformer-based surrogate models are increasingly used to replace expensive first-principles simulation in engineering design. But conventional transformer architectures are often over parameterized for the small, low-dimensional datasets typical of engineering design spaces, where large simulation data is expensive to generate. Under these conditions, excess parameter capacity leads to overfitting rather than improved accuracy, while also incurring unnecessary memory and compute overhead. This motivates a shift towards architectures that focus on additional compute rather than additional learnable parameters. This paper presents a hardware-aware evaluation of three recursive transformer paradigms for surrogate thermo-mechanical analysis of advanced packages: a)Tiny Recursive Model, b) our proposed Depth Recursive transformer, c) and a simple recursive transformer. We systematically compare their predictive performance (Recall, Mean Reciprocal Rank), parameter count, computational complexity (FLOPs), providing practical design guidelines for selecting recursive transformer architectures under resource-constrained scenarios. We validate this principle on two low-dimensional engineering prediction tasks: 1) thermo-mechanical reliability analysis of advanced semiconductor packages, where stress and warpage from thermal cycling must be evaluated repeatedly across a design-of-experiments sweep under costly finite element analysis (FEA). 2) Laplace PDE iterative numerical solver for capacitance field. Overall, recursive weight-sharing transformers provide an effective and generalizable trade-off between prediction accuracy, parameter efficiency, and computational cost for small data engineering surrogate modeling.
Kart-leong Lim
Institute of Microelectronics (IME), Agency for Science, Technology and Research (A*STAR), Singapore
Accurate regional near-surface temperature forecasting is fundamental to short-range weather services and downstream risk assessment. Existing deep learning-based regional forecasters commonly produce a fixed set of future frames on a prescribed grid, limiting their use when forecast products must be evaluated at query-dependent lead times or display resolutions. To overcome these fixed-output constraints, we formulate regional T2M forecasting as query-conditioned continuous spatiotemporal temperature field evaluation and propose the Continuous Spatiotemporal Temperature Forecaster (CSTF), a neural field that turns forecast lead time and output resolution into explicit queries when evaluating 2-m temperature (T2M). Specifically, CSTF first encodes multivariable ERA5 histories into latent meteorological states and then decodes T2M as a coordinate-based field. Accordingly, spatial location, forecast lead time, and output resolution are introduced as queries, enabling standard hourly forecasts, intermediate lead-time diagnostics, and resolution-controllable outputs within a unified field-evaluation framework. Furthermore, to maintain coherence across flexible field queries, we design spatial-gradient, temporal-difference, and scale-consistency objectives that regularize regional thermal structures, lead-wise evolution, and cross-resolution agreement. Experiments on the Southeast China 0-6 h ERA5-Land benchmark demonstrate that CSTF achieves the best aggregate deterministic skill, including a 17.0 percent reduction in Bias, with global-scope diagnostics further illustrating flexible lead-time and resolution-controllable inference.
Chunlei Shi, Jiong Wang, Yi-Lin Wei +4
Department of Automation, Southeast University, Nanjing 210096, China