A numerical investigation of heat transfer mechanisms for the thermal management of small-scale rover wheels in lunar conditions

• Lunar wheels face extreme thermal conditions with no convection, large temperature swings, and continuous radiative exchange driving overall thermal behavior. • Radiation dominates heat transfer, while wheel–regolith conduction has negligible influence, confirming radiative exchange as the primary thermal control mechanism. • Aluminum’s high conductivity ensures compliant temperatures and minimal gradients, outperforming low-conductivity materials like ULTEM and CFRP in lunar environments. • A 1 mm aluminum wheel with α = 0.5, ε = 0.5 provides optimal temperature uniformity, mass efficiency, and structural reliability. • The study delivers a unified thermal-design framework integrating material, geometry, interfaces, and environment, enabling improved wheel thermal management for small lunar rovers. The harsh and dynamic thermal environment of the lunar surface makes effective thermal management a critical requirement for small exploratory rovers. Research on thermal behavior of rover’s wheel zone, however, remains limited and a unified, in-depth framework has yet to emerge. Therefore, this study develops a systematic framework that advances fundamental knowledge of heat transfer mechanisms governing wheel-to-lunar-surface thermal interactions and provides a structured basis for selecting design parameters to support effective thermal management of the wheel zone. The study employs numerical thermal simulations using NX Space Systems Thermal version 2506, in a stepwise parametric approach in which one parameter is varied at a time while carrying forward the recommended configuration to subsequent stages. The influence of wheel thickness, wheel-to-lunar-surface thermal contact conductance, material thermal conductivity, surface thermo-optical properties, and environmental boundary conditions is assessed to evaluate the robustness of the selected design parameters. The results show that a 1 mm-thick aluminum wheel, with a solar absorptivity of 0.5 and an infrared emissivity of 0.5, maintains wheel-zone temperatures within allowable limits across the evaluated hot and cold cases. This configuration also leads to small temperature gradients, which helps enhance the wheel’s thermal resilience. For the cases considered, radiative heat transfer is found to dominate the thermal behavior of the stationary wheel. These outcomes provide clearer insight into wheel-to-lunar-surface thermal interactions and highlight their importance for the thermal management of small lunar rovers.