深槽螺旋钻月壤采样流动特性分析

Analysis on Lunar Regolith Sampling Flow Characteristics of Deep Fluted Augers

面向未来围绕水冰的月球极区月壤采样与原位分析任务需求,使用深槽螺旋钻具实现月壤采样是一种较有优势的方法。但目前关于深槽螺旋钻具对于月壤的采样特性尚未见充分的研究报道,且由于有别于传统浅槽螺旋钻的结构特点,已有理论成果的适用性不佳。本文建立了一种用于描述深槽螺旋钻具对月壤输送特性的动力学模型,能够建立采样效果与钻具结构、钻进规程参数的响应关系。使用CUG-1A模拟月壤,钻进规程参数对螺旋槽内捕获月壤样品密度的影响进行了实验测试,测试结果验证了模型的正确性。研究结果表明:进给速度对于采样密度的影响较小,而钻具转速的影响较大;转速与进给速度的不同组合使深槽螺旋钻的输送模式存在摩擦输送、挤压输送和堵钻3种模式,为获得较好的采样效果,应该将规程参数控制在挤压输送模式的区间内。

For future lunar regolith sampling and in situ analysis with water ice as the theme in the lunar polar region,the deep fluted augers(DFAs)is a promising method to achieve lunar regolith sampling.However,the sampling characteristics of DFAs for lunar regolith have not been fully investigated,and the existed theoretical models are not well applicable due to its structural characteristics that are different from the traditional shallow fluted auger.In this paper,a kinetic model is developed to describe the lunar regolith conveying process by DFAs,so that the sampling effect can be assessed in response to the structural parameters of the DFAs and the drilling operating parameters.Experimental tests on the effect of drilling operating parameters on the density of the regolith sample captured in the flutes were conducted using CUG-1A lunar regolith simulant.The correctness of the model is verified by the test results.The results of this paper show that the feed rate has low impact on the sampling density by DFAs,while the impact of rotational speed is big.Different combinations of rotational speed and feed rate result in three modes of screw conveying status:friction conveying,extrusion conveying and congestion.The operating parameters should be controlled in the extrusion conveying mode to obtain a good sampling effect.