超高速研磨多相微尺度湍流应力机理与边界层激波破坏研究

Ultra High speed grinding is one of the most frequently used methods for acquiring high-precision machined surface, thus the stress mechanisms of multiphase grinding medium in a certain condition of micro-scale turbulence and the destructive rules of shock waves in boundary layers constructing an inevitable way and important theoretical foundation for improving the machining precision and ensuring the surface qualities as estimated. In this research project, we regarded the multiphase grinding medium of solid-liquid-gas materials in micro-scale turbulence as our research carrier, which results to the presentation of a new studying method concerning the mechanics capabilities of micro-scale turbulence and the destructive rules of shock wave together. We first establish the three- dimensional spatial models of micro-scale turbulence's moving routes in the flow field,then a fuzzy gray evaluation system is applied to discuss the fluid kinetic effect which based on the following factors including the high-speed multiphase micro-scale turbulence and the movement of grinding medium particles, etc. Resulting from the physical characteristics of high-speed grinding, the simulation of fluid dynamic movements is implemented on the machined surface topography by solving those energy equations of complex micro-scale turbulence and energetic-optimizing the constructed fluid route models; with the kinetic mechanics model of boundary layer shock waves was constructed, we can understand the cross- relationship between the flow pattern of turbulence particles and their impacting-force parameters, with their quantitative influence on the emergence of boundary layer shock wave in flow field can also be determined as well. The distributing and destructive rules of shock waves are determined by reiterative experiments, then the mutual acting mechanisms among the high-speed flow viscous layer, the machined surface topography, and the destructive stresses of boundary shock waves can also be analyzed in detail. This research work contributes to the development of multiphase micro-scale turbulence theory in high-speed grinding, the innovative technology for studying the destructive rules and the application details of boundary layer shock waves in the grinding flow field as well.

超高速研磨作为获得高精度表面最常见且最有效的加工方法，对其磨削介质在微尺度湍流下的应力机理与边界层激波破坏规律进行研究是提高加工精度与确保质量的必然途径和重要依据。以固-液-气等多相微湍流磨削介质为研究载体，首先建立其流场微尺度湍流的运动轨迹三维空间模型，之后结合模糊灰色评价参数系统探讨基于高速多相微湍流的磨削介质质点运动流体动力学效应，针对超高速研磨的物理特性，通过复杂微湍流能量方程求解与流体路径轨迹模型能量优化，对加工表面微观形貌进行流体动态仿真；建立边界层激波动力学模型，弄清微湍流中质点流态特性和冲击力学参数之间的关系及其对流场边界层激波现象产生的量化影响；实验测定边界层激波效应空间分布与破坏规律，分析确定高速流场粘性层、加工工件表面形貌、边界层激波破坏应力的相互作用机理。研究工作将促进超高速研磨多相微尺度湍流应力理论的发展，为其边界层激波破坏规律及应用研究奠定创新性理论和技术基础。

对超高速研磨中激波破坏与互扰动效应进行抑制是提高强化研磨效率和表面加工质量的必然途径和重要基础。以多相研磨射流介质为研究载体，基于激波矢量-速度同向理论模型探讨激波破坏诱发条件及流体动力响应特征；在获得激波动态数据的基础上，对复杂多相流激波破坏影响模式及其抑制流型进行构建和量化描述；建立研磨表面微观形貌变化对湍流激波破坏的干扰作用模型，通过探索流场磨料质点动态运动刚度、接触区激波扰动边界条件、形貌几何参数弹性力学响应间量化关系，结合模糊集函数运算进行喷射流激波破坏效应对研磨形貌的效果评价以及提出其抑制策略。项目重点揭示了高强度加工负荷条件下射流激波破坏诱发条件，提出其破坏抑制方法及机理思路，同时在跨尺度条件下探讨激波破坏效应与多相流形态间耦合作用规律，为其对研磨表面微观形貌的作用影响及抑制策略提供评价判据，并奠定复杂多相流机理研究创新理论和方法基础。