Thermal Characteristics Analysis For Drilling Process Of Lunar Regolith Sample Drilling Tool

The lunar exploration project is the primary task of the deep space exploration activities ofChina. The lunar regolith is rich in the information of lunar environment and spaceenvironment change, the study of the lunar regolith is not only an important foundation toexplore the solar system evolution, but also a key assessment basis to value the reserves anddistribution of lunar minerals and energy resources.The development of the lunar regolith sample drilling tool is the key process to determinethe success or failure, and the complex thermal environment of lunar surface has put outspecial requirements for the design of structure and drilling procedures control. This paper hasmade the specific modeling and thermal analysis calculating for lunar soil sample collectingprocess of a hollow drill pipe&soft bag sample drilling tool, which is a similar former withSoviet’s lunar probe LUNA24used, in the thermal environment of the lunar surface.According to the data analysis and calculation results of references, this paper establisheda thermal environment analysis model of the lunar surface, and then determined a relative limitcondition of environment parameters. Based on the thermal environment of the lunar surfaceand geometry model of drilling tool, this paper has established a detailed thermal analysismodel for the drilling tool, witch was combined with the mechanical analysis in the drillingprocess, under certain reasonable assumptions and association with the calculation methods ofthe boundary conditions. And also formatted a program using the ANSYS command stream forthe calculation process of the drilling tool in different operating conditions.By the calculation and analysis for the transient thermal response characteristics ofdrilling tool in normal operating condition, bad condition or stop condition, this paperdiscussed the effect of some main order parameters, such as rotating speed and penetration rate,for the highest temperature change and the overall temperature distribution. And according tothe analysis conclusions, this paper carried out a intermittent shuting down method, witch had aperfect performance on the control of high-temperature area. In order to improve the thermalanalysis model established in this paper, the analysis calculation in the ground thermalenvironment was carried out, for the follow-up ground experiment validation.