月壤钻进排屑模型与曲面螺旋式取心钻具研究

发布时间：2018-07-05 10:37

本文选题：月球钻探 + 取心钻头　；参考：《哈尔滨工业大学》2016年博士论文

【摘要】：我国探月三期工程核心目标是实现月球次表层月壤钻进采样并返回,钻进采样器搭载的钻具是整个工程的执行末端,钻具与月壤直接接触,其外部结构设计对分系统钻进负载、钻头温度、取样率等方面有决定性影响。钻具的外部结构包含钻杆排屑结构、钻头排屑结构、钻头取样口结构和钻头岩石切削结构等几个部分。本论文以月壤的螺旋排屑过程建模为基础,对钻具结构进行设计优化研究,并通过模拟月壤钻取实验及离散单元仿真进行验证。资料显示月壤是一种流动性较差粉体物质,同时处于月表没有水和大气的环境中。在月球表层回转钻进采样过程中月壤碎屑需要通过钻头与钻杆的螺旋排屑结构排出钻进区域,若排屑不畅会导致钻具负载增加甚至卡钻。本文首先分析了月壤在钻具螺旋槽内的流动特征,定义了钻具的理想排屑状态。建立月壤碎屑流动的通量平衡关系,利用排屑槽内月壤的运动学及力学分析建立起月壤流动状态与钻具结构参数之间的关系模型,定义排屑能力系数来表征钻具在指定钻进规程下的月壤碎屑移除能力。为提高模型精度,对影响月壤排屑流动的钻具回转动力学因素,拟流体粘滞效应等进行了分析,并设定了相应的修正系数。在月壤螺旋排屑模型的基础上,对钻杆结构参数进行优化设计,通过钻杆对模拟月壤的排屑实验对排屑模型及构型参数进行验证。另外还给出了钻杆排屑轴向力与扭矩的转换关系,并在复杂钻进规程实验中进行了验证。为从细观角度观测月壤在排屑槽内的流动状态,对月壤进行了离散元建模并参数匹配,离散元仿真结果为排屑流动假设及排屑模型理论提供支撑。在传统探月钻具设计中,钻具排屑负载主要集中于钻头与钻杆连接处,该位置月壤滞流严重,本文提出实现了钻头钻杆共体设计,将排屑能力设计作为钻头构型设计的重点,以提升钻具整体性能。依据月壤在螺旋槽内的排屑模型,利用空间微分几何建模方法设计了曲面基体和空间螺旋曲线包络的排屑通道,该排屑通道与钻杆结构参数一致,其设计排屑能力与钻杆相匹配。通过多种典型构型钻头钻进负载实验进行对比,钻进对象包括小粒径模拟月壤及临界尺度模拟月壤。利用离散元仿真,定性观察了小尺度月壤及临界尺度月壤在不同构型钻头排屑槽内的流动及受力状态,对负载偏差进行了解释。钻头取样口结构设计对其取样能力的影响是一个复杂的难题,具有较强的随机性,本文对钻头取样口结构发生变化时,目标取样区土体的失效形式进行了分析,给出了取样率的预测模型,并通过取样实验进行了验证。利用离散元仿真方法研究了钻具对月壤周向层理信息的影响。本文还研究了在曲面螺旋钻头构型的基础上实现月岩钻进的工程方案,提出CBN磨粒镍基电铸及硬质合金切削具镶嵌两种方法,分析了两种方法在岩石钻进特性上的差异,并通过模拟月岩钻进实验进行了对比验证。
[Abstract]:The core goal of the three phase of our lunar exploration project is to realize the lunar subsurface lunar soil drilling sampling and return. The drilling tools carried by the drilling sampler are the end of the whole project. The drilling tools are directly exposed to the lunar soil. The external structure design has a decisive influence on the drilling load, the bit temperature, the sampling rate and so on. The external structure package of the drill tool. In this paper, the design optimization of the drilling tool structure is studied based on the modeling of the spiral chipping process of the lunar soil. The data shows that the lunar soil is a flow. In the course of rotary drilling of the moon surface, the debris of the lunar soil needs to discharge the drilling area through the spiral cuttings structure of the drill and drill rod during the lunar surface rotation drilling and sampling. The flow characteristics of the drilling tools are defined. The flux equilibrium relationship of the lunar soil debris flow is established. The relationship model between the flow state of the lunar soil and the structural parameters of the drilling tools is established by using the kinematic and mechanical analysis of the lunar soil in the chute trough, and the cuttings capacity coefficient is defined to characterize the lunar soil debris under the specified drilling regulation. In order to improve the accuracy of the model, the dynamics factor of drilling tool rotation and the viscous effect of the fluid are analyzed, and the corresponding correction coefficient is set up. On the basis of the lunar spiral cuttings model, the structure parameters of the drill rod are optimized and the drilling rod is used to exhaust the chip experiment of the simulated lunar soil. The model and the configuration parameters are verified. In addition, the conversion relation between the axial force and the torque of the drill rod is also given, and the verification is carried out in the complicated drilling regulation experiment. In order to observe the flow state of the lunar soil in the chip slot from the meso angle, the discrete element modeling and parameter matching are carried out on the lunar soil, and the discrete element simulation results are the assumption of the chip flow hypothesis. In the traditional lunar exploration tool design, the drilling tool chip load is mainly concentrated on the connection between the drill and the drill rod. The position of this position is very serious. This paper puts forward the design of the drill rod in this paper. The design of the cuttings capacity is the key point of the bit configuration design to improve the overall performance of the drill. The chip removal model in the spiral groove is designed by space differential geometry modeling method, which is consistent with the structure parameters of the drill rod, and the chip ability of the design is matched with the drill rod. The drilling object includes the small particle diameter model through a variety of typical configuration bits drilling in negative load experiment. The simulated lunar soil and critical scale simulated lunar soil. Using the discrete element simulation, the flow and stress state of the small scale lunar soil and the critical scale lunar soil in the cuttings groove of different configuration bits are qualitatively observed. The load deviation is explained. The structure design of the bit sampling port is a complicated problem and has a strong random problem. In this paper, the failure form of the soil in the target sampling area is analyzed in this paper when the structure of the bit sampling mouth is changed. The prediction model of the sampling rate is given and verified by the sampling experiment. The influence of the drilling tool on the bedding information of the lunar soil is studied by the method of discrete element simulation. The configuration of the spiral bit is also studied in this paper. On the basis of the project, two methods of CBN abrasive nickel based electroforming and cemented carbide cutting tool inlay are put forward. The difference between the two methods in rock drilling characteristics is analyzed, and the comparison and verification of the simulated lunar rock drilling experiments are carried out.
【学位授予单位】：哈尔滨工业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：P184;V476.3

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