模拟月面环境钻进过程热特性研究

Research on the Thermal Features of the Drilling Process Under the Simulated Lunar Surface Environment

根据实际月面采样任务需求,月壤钻取采样器须在真空条件下,实现无辅助冷却介质的连续钻进取心工作,这极易导致钻头温度快速升高,影响采样任务的可靠进行。因此,为深入研究钻进过程的热特性,通过分析钻头切削具与孔底月壤的切削和摩擦机理,建立钻头在钻进过程中的温升模型,归纳影响钻头温升的主要因素。根据月面真空条件下的月壤环境,制备真空度低于10 Pa、钻进深度不少于2 m的模拟月壤,并开展钻进过程热特性试验。试验结果表明钻头前端切削具的温升与钻压力存在很强的正相关性,与钻头扭矩相关性较弱。基于试验结果对温升模型中的相关性系数进行修正,拟合出钻头温升曲线,并与试验实测结果进行对比,实现了钻进过程热特性的定性分析。

According to the requirements of the lunar surface sampling task,The lunar regolith sampler need to drill under vacuum conditions,and realize the continuous drilling without aided-cooling medium. It is very easy to cause a rapid temperature rise on bit,which resulted in making effect on the reliability of the sampling task. Thus,in order to study on the thermal characteristics of the bit in drilling process,the cutting and friction mechanism between blade on bit and the lunar soil is analyzed in this paper. A temperature rise model of bit is established,and the main factors that influence the temperature rise of the drill bit are obtained. According to the lunar vacuum environment,the 2 m drilling depth lunar soil simulant is prepared,and its vacuum degree below 10 Pa,simultaneously,the thermal feature drilling tests are performed. The experimental results show that there is a strong positive correlation between the temperature rise and the weight on bit at the front of the drill bit,and the correlation on bit torque is weak. The correlation coefficient of the model of the temperature rise prediction is modified based on the test results. The fitting curve of the temperature rise is obtained,and the comparison of the results between fitting and test has been carried out. The qualitative analysis of the thermal characteristics of the bit in drilling process is acquired.