Simulation Study on Heat Generation by Water-Ice Penetration Impact in Lunar Soil based on the Discrete Element Method

The CE-7 mission plans to adopt a drilling and sampling scheme to obtain in-situ lunar soil water ice samples with layering information. In the vacuum and low-temperature environment of the lunar polar regions, the lunar soil water ice cemented material is highly sensitive to temperature changes and is prone to phase change and escape, resulting in the loss of layering information and a reduction in its scientific value, which poses a significant challenge to the sampling technology. Based on the discrete element method, the heat generation simulation of the temperature field of the ultrasonic drill penetrating and impacting the simulated lunar soil water ice with different water contents and initial temperatures in a vacuum and low-temperature environment was conducted. A theoretical temperature field calculation model was established, and a contact model program was developed through the EDEM software API interface. Using the latest thermal parameters of lunar soil water ice, the temperature field changes during the ultrasonic drill’s penetration of lunar soil water ice in a vacuum and low-temperature environment were simulated and analyzed.