Numerical study on the design of heating source arrangements to enhance thermal ice coring performance

Thermal ice coring is a critical technology for obtaining ice cores in polar research, yet achieving higher drilling efficiency and core integrity remains a key engineering challenge. Although the design of the internal heat source critically determines the thermal performance of the drill bit, its influence on system heat transfer and ice-core preservation is not fully quantified. To address this, this study develops a three-dimensional, transient, multi-physics coupled numerical model using MATLAB to simulate the complex heat transfer involving phase change and fluid flow during the coring process. The model, solved by the finite volume method (FVM) and validated against experimental data (maximum rate of penetration ( ROP ) error < 12.85%), systematically investigates three distinct heating wire winding configurations: equidistant helical winding (EHW), equal coil height winding (ECHW), and equal coil height bottom-concentrated winding (ECHBW). Results demonstrate that the ECHBW configuration optimizes the heat transfer pathway by reducing the average distance from the heat source to the drill bit's working face by 2.15%, thereby increasing the bottom's average temperature by 6.48%. Compared to the conventional EHW design, the ECHW pattern enhances the temperature uniformity at the bit bottom by 73.67%, increases the ROP by 4.61–6.37% at 2100 W, reduces heat loss to meltwater by 9.69% and thermal disturbance to the ice core by 1.97%, consequently decreasing the melted ice volume by 1.44%. Furthermore, higher heating power is shown to localize the thermal impact zone despite elevating peak temperatures, and a near-linear positive correlation is found between ambient temperature and ROP within the range of −40 °C to −15 °C, without aggravating core melting. This work provides a validated numerical tool and clear design principles for optimizing the thermal management of coring bits, contributing to more efficient and less invasive ice core sampling technology.