液滴碰撞曲面液膜波动特性及对换热特征的作用机理研究

项目名称： 液滴碰撞曲面液膜波动特性及对换热特征的作用机理研究

项目编号： No.51506023

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 能源与动力工程

项目作者： 梁刚涛

作者单位： 大连理工大学

项目金额： 21万元

中文摘要： 液滴冲击曲面作为水平管降膜蒸发器、丝网除沫器等工业设备中的典型流动过程，对其所涉及基础科学问题的探索对此类设备的关键技术开发具有重要价值。本项目将开展单/双液滴碰撞弯曲表面液膜过程研究，采用实验观测辅以数值模拟的手段，着重于碰撞后液膜波动的演变规律以及波动对换热特征作用的物理机制。通过反复观测液滴与不同曲率弯曲表面液膜的动态接触过程，探明固体曲面效应、波干涉与叠加效应对波动特性的影响。另外，液膜与曲面单相、相变换热条件下，作出曲面液膜在撞击过程中波动幅度和频率、内部微对流、表面蒸发的定量分析，从而实现波动过程对换热性能贡献的量化研究。在此基础上，阐明液滴碰撞弯曲表面液膜波动的宏观形态与微观热质传递过程的理论内涵，初步建立可预测液膜波动随时空变化的理论模型，以期丰富液滴碰撞领域的理论探索。

中文关键词： 液滴撞击；曲面液膜；液膜波动；曲率

英文摘要： Drop impact on a curved surface is the typical flow process in horizontal-tube falling film evaporators and wire mesh demisters. Exploring its related fundamental scientific problems is crucial for the key technology development of such equipment. This project will carry out research about single/dual-drop impinging on curved films, adopting experimental observation and numerical simulation as the studying methods. The focus lies in the film fluctuation evolution after impact and the influential mechanism of fluctuation on heat transfer characteristics. With support of observing the dynamic contacting process between the drop and film repeatedly, influences of curved surface effect, wave interference and overlay on the fluctuation can be revealed. Besides, under the single phase and phase change conditions, quantitative work about wave amplitude and frequency, inner convection, surface evaporation will be conducted, so that the quantitative impact of fluctuation on heat transfer performance can be analyzed efficiently. Based on the two aspects, the theoretical connotation in macro morphology and micro heat mass transfer of the fluctuation will be provided and the theoretical model used to predict the fluctuation temporal and spatial evolution will also be established, to enrich the theoretical exploration in the drop impinging field.

英文关键词： drop impact;curved film;film fluctuation;curvature