【作者】 穆磊；

【导师】 贺志宏；

【作者基本信息】 哈尔滨工业大学 ， 热能与动力工程， 2010， 硕士

【摘要】 半透明颗粒相变过程是一个复杂的多场耦合传热过程,往往伴随着辐射吸收和发射等光学行为以及膨胀变形、收缩破裂等力学行为。了解和掌握这些机制和行为对相关工程技术领域的过程控制、优化设计具有重要意义,如热喷涂技术、液滴燃烧、空间液滴散热技术、反应堆事故、太阳能热利用等等。高温颗粒相变过程中的辐射导热耦合传热模拟,对于准确分析高温颗粒的相变过程是非常必要的。由于相变过程中存在相界面移动和变形等问题,传统的基于网格法的数值模拟手段求解这类问题需要复杂和繁琐的网格初置与重构过程,而无网格法不依赖于网格,对于求解域连续变化等复杂问题的求解具有很大优势。本文主要目的是将无网格SPH法引入到相变过程中的辐射-导热耦合传热过程的分析研究当中来,在此过程中忽略力学效应,假设颗粒在发生相变的过程中不发生形变。论文的主要工作包括:(1)相变导热问题的无网格SPH法研究推导了相变导热方程及其边界条件的SPH法离散格式,编制了计算程序;对第一类和第三类边界条件下的二维非稳态相变导热过程的温度场、相界面位置进行了数值模拟,与解析解比对分析,考察了SPH法在处理相变导热问题上的计算精度和适应性。(2)辐射传递方程求解的无网格SPH法研究推导了无散射介质辐射传递方程及边界条件的SPH法离散格式,编制了计算程序;对二维方形空腔内的吸收发射性介质辐射换热进行了模拟计算,与有限体积法的标准程序解进行了比对分析,考察了SPH法在处理辐射传递问题上的适用性。(3)相变过程辐射导热耦合传热模拟的SPH法研究推导了含辐射源项的相变过程焓方程的SPH离散格式,将相变导热问题的SPH法与辐射传递问题的SPH相结合,编制了计算程序;与二维相变辐射导热耦合换热的有限体积法标准解进行比对,验证了SPH法的可靠性;对半透明颗粒相变过程传热进行了模拟。更多还原

【Abstract】 It is a complex multi-field coupled heat transfer process for semitransparent particle with phase change, there often accompanied by absorption and emission of radiation and swell distortion and shrinkage splinter of mechanical behavior of fracture. Which is very important to process control and optimization design in related to the field with understand and master these mechanisms and behaviors, such as thermal spraying, droplet combustion, droplet cooling space technology, reactor accidents, solar thermal, etc. The radiation and conduction coupling simulation of particle in the high-temperature is necessary for accurate analysis the process of the phase change. Because there exists the phase interface movement and deformation problem in the process of phase change, the traditional gird method need to build a new gird repeating, this work is complex and fasting time. But meshless method does not depend on gird, so it’s a great advantage for solving complex problems such as continuous field changes.The purpose of this paper is to solving the radiation-conduction problems with the meshless SPH in the process of the phase change, we can not consider the mechanical behavior of fracture in this work. And suppose it is not phase change in the process of deformation. Thesis include:(1) The study on the conduction heat transfer problem in the process of phase change by meshless SPH method We build the conduction function with phase change and derived the SPH method discrete format of the boundary conditions, then create a computer program. Calculate the temperature field and interface position of the two-dimensional steady-state conduction heat transfer in the phase change with the fist and third boundary conditions. Compared with the analysis to study the accuracy and adaptability of the meshless SPH method by applied which to phase change.(2) The study on the radiation heat transfer with meshless SPH method We build the radiation transfer function without scattering media and derive the discrete format SPH method of the boundary conditions, then create the computer program. Calculate the radiation heat transfer of the absorption media of the two-dimensional square cavity. Compared with the finite volume solutions of the standard procedures, to investigate the meshless SPH method is used to dealing with the radiation problem.(3) Study on the heat transfer of coupled radiation and conduction in the process of phase change with the meshless SPH method We derive the discrete format of the power conduction of the process of the phase change with the sources of the radiation. Combine the conduction heat transfer of the phase change and radiation transfer problem, then create computer program. Calculate the couple radiation and conduction heat transfer of the two-dimension phase change, compared with the finite volume solving of standard to verify the reliability of SPH method. In the last calculate the process of the phase change of the semitransparent particle.更多还原