R134a工质作用下电场对气泡的作用研究+ANSYS模拟
时间:2016-12-18 10:28 来源:毕业论文 作者:毕业论文 点击:次
| 摘要：为了探明外加电场对于气泡的作用，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R134a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。分别向上极板施加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。结果表明，气泡周围电场分布不再均匀，随着施加的直流高压电场的增大，场强也逐渐增大，随着两侧的场强增大，而靠近气泡顶部及底部附近的场强降低。随着气泡数量的增多，场强对气泡的作用相应变弱。场强使气泡周围电场特性发生改变，使EHD强化效果增强。4482 关键词：电水动力学 气泡 均匀电场 电场特性 数值模拟 EFFECT ON BUBBLES IN ELECTRIC FIELD IN ETHYL ACETATE WORKING FLIUDS ABSTRACT： In order to proven the role of the applied electric field for the bubbles. 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 R134a. 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 departure of several bubbles. The results indicate that the electric field distribution around the bubble is no longer uniform .The field strength also is increased with the increase of the applied direct-current high voltage electric field, and the electric fields of the two sides are enhanced while near the top and bottom areas the electric fields decrease. As the numbers of bubbles become more, the effect of electric field on bubbles becomes weaker. So the conclusion is reached that the electric field distribution around the bubbles will be changed by the electric field and thus will enhance the effect of EHD. KEYWORDS: EHD(electro hydro dynamics) bubbles uniform electric field electric characteristics numerical simulations 目录 目录 2 1绪 论 1 1.1课题选择依据及研究意义 1 1.2强化沸腾传热技术的研究历程 2 1.3EHD强化沸腾换热的研究现状 4 1.3.1电场特性对EHD强化沸腾换热的影响 4 1.3.2 工质性质对EHD强化沸腾换热的影响 6 1.3.3 热流密度对EHD强化沸腾换热的影响 6 2 EHD强化沸腾换热理论基础 7 2.1 EHD强化传热机理 7 2.2 EHD强化传热的优势 10 2.3电场在R134a工质作用下气泡的行为变化 11 2.4 电场对气泡动力学特性的影响 14 3 ANSYS软件的应用 17 3.1简介ANSYS软件 17 3.1.1 软件功能简介 17 3.1.2 前处理模块PREP7 18 3.1.3 求解模块SOLUTION 19 3.1.4 后处理模块POST1和POST26 20 3.2电磁场有限元分析简介 21 3.2.1 电磁场基本理论 21 3.2.2 电磁场有限元分析 22 3.3有限元法的计算步骤 23 3.3.1 构建模型 23 3.3.2 施加载荷计算 24 3.3.3 求解 24 3.3.4 后处理 24 4 电场作用下工质对气泡的影响 25 4.1物理问题描述 25 4.2电场控制方程及边界条件 27 (责任编辑：qin) |