R11工质作用下电场对气泡的作用
时间:2019-08-16 21:46 来源:毕业论文 作者:毕业论文 点击:次
| 摘要：电水动力学EHD强化换热是指在换热表面的流体中施加一电场，利用电场、流场和温度场之间的相互作用达到强化传热效果的一门新型传热强化技术。为了进一步探索电场对汽泡影响所带来的强化传热作用和机理，本课题针对均匀电场下气泡周围电场分布状况进行研究。选用了R11 工质，利用ANSYS 计算软件，编程求解出不同电场作用下气泡周围场强分布特性。分别向上极板15kv,20kv,25kv 的直流高压电场，对单个气泡附壁、脱离及多个气泡生成并部分脱离时电场分布特性进行了数值模拟。电场使气泡运动规律和行为特征发生改变，从而改变流场结构，并使热量的传递得到强化，所以气泡起着核心纽带作用。但是，因为电场和热流场相互干涉影响，所以气泡行为及运动规律等内容的研究，成为电场强化传热技术研究的难点与重点。38473 毕业论文关键词： 电水动力学；匀强电场；数值模拟；流场结构 Effect on Bubbles in Electric Field in R502 Working Fliuds ABSTRACT ： EHD heat transfer enhancement (electro hydrodynamic) refers to a new mode applying an electirc field in the fluid of heat transfer surface and using electric field, flow field and temperature field of heat transfer enhancement interaction to achieve the purpose of actively strengthening heat transfer. In order to further explore the role and mechanism of applied electric field in bubble, This research focuses on the numerical simulation of the electric field distribution around the bubble that is under the uniform electric field. The working fluid used is R502. ANSYS is used to simulate the electric field distribution of the bubble under different uniform electric field. The top plate is respectively exerted 15kv, 20kv and 25kv direct-current high voltage electric field, the simulations is carried out when a bubble attaches, departs or when the formation with partial attachment and departure of several bubbles. Electric field makes the bubble behavior characteristics and the motion law of change, which changes the flow field structure and contributes heat transfer strengthening, so bubbles play a core link function. While on account of inertaction between the elctric field and thermal flow field, the bubble behavior and movement law, etc, become a research, which is emphasis and difficulty in heat transfer technology of electric field. KEYWORDS: EHD (electro hydrodynamics)；uniform electric field ；numerical simulations；flow field structure 目录 1.绪论.5 1.1 课题的目的和意义 5 1.2 国内外研究现状与水平 5 1.3 强化沸腾传热技术的研究历程.6 1.4 强化沸腾换热的研究方向 6 1.4.1 基础性研究.7 1.4.2 实用性研究.7 1.5 R11工质参数介绍7 2.EHD强化沸腾传热的机理分析9 2.1 EHD力对气液界面的作用.11 3.ANSYS 软件的应用13 3.1 简介ANSYS 软件.13 3.2 技术种类13 3.3 软件开发应用14 3.3.1 能实现电子设备的互联14 3.3.2 仿真各种类型的结构材料14 3.3.3 简化复杂流体动力学工程问题14 3.3.4 基于模型的系统和嵌入式软件开发. 15 3.4 分析类型15 3.5 前处理16 3.5.1 实体建模. 16 3.5.2 网络划分17 3.5.3 施加载荷17 3.6 后处理17 3.7 电磁场的有限元分析18 3.8 有限元法的计算步骤19 3.8.1 构建模型19 3.8.2 施加载荷计算20 3.8.3 求解20 3.8.4 后处理20 4.软件模拟图及计算结果分析22 4.1 气泡周围的电势分布. 22 5.结论37 5.1电势的变化 37 5.2 场强的变化. 37 (责任编辑：qin) |