风致屋面积雪分布特性风洞实验与数值模拟研究

发布时间：2018-01-23 14:33

本文关键词： 风雪两相流数值模拟欧拉混合模型拉格朗日随机模型风洞试验模型相似律屋面积雪分布　出处：《西南交通大学》2014年博士论文　论文类型：学位论文

【摘要】：介绍了风吹雪带来的自然灾害,对国内外相关研究文献进行了分类和回顾,总结并归纳了风吹雪的基本理论,并进行了简要分析。对若干种典型屋面的建筑结构,通过数值模拟和风洞试验两种途径对风致屋面积雪分布进行了研究,主要内容如下：1.基于欧拉两流体混合模型和Wilcox最新改进的κ-ω湍流模型,开发风雪两相流数值模拟分析程序Snow2D。模拟中为考虑积雪对流动的影响,计算区域的积雪边界采用了时变自适应变形技术。为提高计算过程的稳健,程序中还应用了一些较新的数值方法,并对程序进行了验证。2.利用Snow2D对一典型阶梯形屋面及两种斜坡屋面的风致屋面积雪分布进行数值模拟,分析了屋面流动特性,获得了若干状态下屋面的积雪系数以及屋面雪深分布随时间发展历程,分析了不同入流速度比对屋面积雪分布特性的影响。3.基于拉格朗日随机模型和Snow2D单相流模式,开发了风致雪粒迁移运动模拟分析程序,通过PDF随机采样模拟了粒子运动的Monte Carlo过程。采用粒子单元位置的优化搜索方法,提高了程序计算效率。考察了不同粒子大小及不同风速对雪粒运动的影响,然后对典型阶梯形屋面的积雪分布进行模拟,考察了屋面的积雪效率,获得了屋面积雪分布随时间发展历程。4.从几何、运动以及动力学等方面,分析了风吹雪风洞试验模型需要满足的模型相似律,归纳了模型主要相似性参数。5.采用细石英砂作为吹雪模型粒子,对一典型阶梯形屋面及两种斜坡屋面的风致屋面积雪分布进行了风洞试验研究。首先对流场进行了测量,分析了运动粒子对流动的影响,然后对若干种工况下的屋面积雪分布进行风洞模拟试验,测量了不同时间、风速以及风向角下的屋面粒子分布特性,并对屋面粒子质量流率与风速及风向角的关系进行了分析。6.对积雪分布数值模拟结果以及风洞试验结果与文献中的观测结果进行了综合比较,并与国内外建筑结构荷载规范中的相关条文进行了对比和分析。
[Abstract]:This paper introduces the natural disasters caused by wind and snow, classifies and reviews the relevant research literature at home and abroad, summarizes and summarizes the basic theory of wind and snow blowing. Through numerical simulation and wind tunnel test, the distribution of snow cover on wind-induced roof is studied by means of numerical simulation and wind tunnel test. The main contents are as follows: 1. Based on Euler's two-fluid mixing model and Wilcox's newly improved 魏-蠅 turbulence model. In order to consider the influence of snow cover on the flow, the time-varying adaptive deformation technique is used to calculate the snow cover boundary in order to improve the robustness of the calculation process. Some new numerical methods are also used in the program, and the program is verified. 2. The distribution of snow cover caused by wind in a typical stepped roof and two kinds of sloping roof is simulated by Snow2D. The characteristics of roof flow are analyzed, and the snow coefficient and snow depth distribution over time are obtained. Based on the Lagrangian stochastic model and Snow2D single-phase flow model, a simulation analysis program for the movement of wind-induced snow particles is developed. The Monte Carlo process of particle motion is simulated by PDF random sampling, and the optimal searching method of particle unit position is adopted. The effect of different particle size and different wind speed on the snow particle movement is investigated. Then the snow cover distribution of typical stepped roof is simulated and the snow cover efficiency is investigated. The history of snow cover distribution over time is obtained. 4. The similarity law of wind tunnel model is analyzed from geometry, motion and dynamics. The main similarity parameters of the model. 5. The fine quartz sand is used as the snow blowing model particle. The wind tunnel experimental study on the snow distribution of a typical stepped roof and two kinds of sloping roofs is carried out. Firstly, the flow field is measured, and the effect of moving particles on the flow is analyzed. Then the wind tunnel simulation test was carried out on the snow cover distribution under several operating conditions, and the particle distribution characteristics of the roof under different time, wind speed and wind direction angle were measured. The relationship between the mass flow rate of roof particle and wind speed and wind direction angle is analyzed. 6. The numerical simulation results of snow cover distribution and the results of wind tunnel test are compared with the observed results in literature. The comparison and analysis are made with the relevant provisions of the load code for building structures at home and abroad.
【学位授予单位】：西南交通大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TU312.1

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