约束模块在软性磨粒流精整加工中的应用及其设计方法-机械电子工程专业论文.docx

浙江工业人学硕士学位论文约束模块在软性磨粒流精整于jl-r-中的应用及其设计方法摘要约束模块作为软性磨粒流加工方法的核心构件，不仅能实现对湍流流场的按 需调控，且可以完成有效加工区域的拓展与迁移。针对此问题，本文提出了一种 面向软性磨粒流加工的约束模块设计方法，并完成了相关验证实验，主要工作结 论描述如下：(1)基于固．液两相流边界层理论建立了可应对约束流道环境下软性磨粒流 磨粒入射肇面过程的颗粒运动轨迹数学模型。针对稀疏磨粒流在湍流状态下的壁 面接触问题，提出了一种游离磨粒入射壁面速度与角度计算方法，为软性磨粒流 近壁区域微切削效应提供了可靠依据。(2)针对具体的约束流道条件，基于可实现(Realizable)缸s模型和混合 (Mixture)模型建立了软性磨粒流加工过程动力学模型。针对磨粒流经过弧形约束 模块的绕流偏转现象，利用涡旋结构分析方法揭示了软性磨粒流加工过程中表面 动压力不对称机理。(3)提出了可满足软性磨粒流加工需求的约束模块普适设计方法。基于软性 磨粒流加工实验平台，设计了可移动式约束模块，并完成了加工实验。结果证明： 约束突起结构对动压力、磨粒体积分数、磨粒入射速度有明显调控作用，且可以 实现有效加工区域的迁移，证明了本文方法的可行性与有效性。关键词：软性磨粒流，精整加工，约束模块，边界层，颗粒入射模型，设计 方法浙江工业大学硕士学位论文APPLICATIoN AND DESIGN METHoD oF CoN． STRAINT CoMPoNENT IN SoFT ABRASIVE FLOW MACHININGABSTRACTConstraint component，which is the core part in soft abrasive flow machining method，can realize controlling of turbulent flow field according to needs and accom- plish expending and moving of effective machining region．This article presented a design method of constraint component towards soft abrasive flow machining，and completed interrelated confirmatory experiment．The main conclusions are described as follows．(1)Based on solid-liquid two-phase flow boundary layer theory，a mathematical model of trajectory of particle motion was set up to cope with the course of abrasive injection into the wall in the situation of constrained flow passage．To solve the prob— lem of wall contact of light concentration abrasive flow in turbulent condition，a nu- merical method was put forward to calculate injection velocity and angle of flee abra． sive．It provided the reliable basis for micro-cutting effect of soft abrasive flow in near-wall region．(2)On the basis of Realizable k-e model and Mixture model，a dynamic model of soft abrasive flow machining process was established for concrete condition of con． strained flow passages．Mechanism of asymmetry of dynamic pressure on workpiece surface Was revealed by analyzing the structure of eddy to explain the deflection phe—nomenon in circumferential motion of abrasive flo