基于去层化效应分析的密度分层演化过程研究

项目名称： 基于去层化效应分析的密度分层演化过程研究

项目编号： No.51506025

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： 任婧杰

作者单位： 大连理工大学

项目金额： 20万元

中文摘要： 密度分层现象普遍存在于液化气体燃料储运、太阳能集热储能、核能发电等能源利用领域的关键设备。其形成后，将对设备的安全和高效运行产生直接影响，对于不同设备，这些影响有的是有利的，有的是不利的。研究密度分层的致因和演变机理，对于在能源生产和利用的关键环节中有效地利用或避免密度分层的影响具有重要的科学意义和应用价值。尽管密度分层形成的原因不尽相同，但是究其机理，都是浮力驱动自然对流流动的结果，涉及到热边界层浮升流动和主流区惯性流动与补偿流动对密度层化和去层化效应的影响及二者的耦合作用机理等科学问题。本项目应用流体动力学和传热传质学原理，采用实验与数值模拟相结合的方法研究热/组分浮力对液体介质密度分层的去层化作用机理；揭示密度层化和去层化机制耦合作用下的密度分层演化过程的流体动力学和传热传质学机理；研究密度分层的存在与消失对典型工业装备的影响规律；提出在具体设备中维持和消除密度分层的方法。

中文关键词： 密度分层；去层化效应；热/组分浮力；演化机理

英文摘要： Density stratification is a common phenomenon in the liquefied gas fuel storage, solar thermal energy storage, nuclear power and other crucial equipment in the field of energy utilization. After formation, it will have a direct impact on the safety and efficient operation of the equipment. For different devices, the effects may be positive or negative. It is of important scientific significance and application value to research the evolution mechanism of thermal-component buoyancy driving density stratification for avoiding or utilizing its effect on the energy production and application. Although the cause of density stratification is not the same, but in essence, it is the result of buoyancy driving natural convection flows. The related scientific problems are the influence of the thermal boundary layer floating flow, the bulk inertial flow and the bulk compensation flow on density stratification and de-stratification, and the coupling mechanism between them. This project will study the following contents using experimental and numerical methods basing on the principle of fluid dynamics and heat-mass transfer: (1) the acting mechanism of thermal-component buoyancy on the de-stratification; (2) the evolution mechanism of density stratification under the coupling of stratification and de-stratification action;(3) the influence law of the existance and disappearance of density stratification on the typical industrial equipment;(4) the measures of maintaining or eliminating density stratification in specific device.

英文关键词： density stratification;de-stratification effect;thermal-component buoyancy;evolution mechanism