Seven-node Model

Author: CislunarSpace

Site: https://cislunarspace.cn

Definition

The seven-node model divides the stratospheric airship thermodynamic system into seven distributed nodes for refined modeling. Compared to the two-node model, it can capture spatially non-uniform temperature distribution and local thermal effects.

Node Distribution

NodeRegionDescription
1Windward skinDirectly solar heated or wind-cooled
2Leeward skinShadow area, radiative cooling
3Top skinMaximum solar direct exposure
4Bottom skinReceives earth albedo
5Helium main bodyInternal gas body
6BallonetAuxiliary airbag region
7Structural frameLoad-bearing structure

Mathematical Formulation

General Form

CidTidt=∑j=17Qi,jcond+Qiext+QiintC_i \frac{dT_i}{dt} = \sum_{j=1}^{7} Q_{i,j}^{cond} + Q_i^{ext} + Q_i^{int}

Conduction Terms

Qi,jcond=kijAijdij(Tj−Ti)Q_{i,j}^{cond} = \frac{k_{ij}A_{ij}}{d_{ij}}(T_j - T_i)

Model Validation

Test ConditionTwo-node ErrorSeven-node Error
Daytime high temp±5 K±1 K
Nighttime low temp±8 K±2 K
Sunrise/sunset±10 K±3 K

References

  • Liu Y, et al. Seven-node Thermal Model for Stratospheric Airship[J]. AIAA Journal of Thermophysics, 2024.
  • Wang H, Chen W. Refined Thermodynamic Modeling for Stratospheric Airship[J]. Acta Aeronautica, 2025.