周边树木对低矮房屋挡风性能的研究

发布时间：2018-06-16 07:15

本文选题：CFD + 计算流体力学　；参考：《北京交通大学》2013年硕士论文

【摘要】：为了创造舒适的生活环境,房屋周边一般会有树木环绕,气流在流动过程中受到这些树木阻碍,将在其下游形成一个遮蔽区,在该区域来流风速降低,湍流强度增加,大气湍流中的涡旋结构减弱。通过在房屋周围合理植树,可以很好地降低风速,改善局部风环境,特别是对低矮建筑的角部、边缘和屋脊等区域的局部风压改善效果明显。本文主要采用数值模拟的方法研究树木对低矮建筑物的挡风性能,完成的主要工作有： 1、基于RANS的CFD精细化数值模拟技术。通过TTU模型的实测数据,研究了数值模拟中参数的设置,包括计算域大小、最小网格尺寸、湍流模型选择、边界条件设置以及控制方程的离散求解算法等,用以提高CFD数值模拟的精度。 2、树木挡风性能的数值模拟。利用多孔介质模拟的附加源项法,建立树木挡风性能数值模拟方法,通过与实测数据对比,验证了数值模型的有效性。通过改变树冠疏透性、树木高度、树冠形状以及树木间距等参数,研究了树木下游的风场特性；给出了风压、风速在不同工况下的分布特征,并通过速度分布曲线描述了树木下游的风速变化规律。结果表明,树冠疏透率和树木高度是影响其下游流场的主要因素。 3、树木对低矮房屋的挡风性能研究。研究了树冠疏透性、树木高度、树冠形状等树木参数以及屋面坡角、檐口形状、树木与房屋的间距等房屋参数的不同工况,得到了树木对低矮房屋风压的影响规律。基于上述研究,给出了房屋周边的风速、风压分布特征,分析了低矮房屋风压在不同工况下的变化趋势,为增强低矮房屋的抗风能力提供了理论参考和建议。
[Abstract]:In order to create a comfortable living environment, the house is usually surrounded by trees, and the air flow is blocked by these trees during the flow process, which forms a sheltered area downstream, where the wind speed decreases and the turbulence intensity increases. The vortex structure in atmospheric turbulence weakens. By planting trees reasonably around the building, the wind speed can be reduced and the local wind environment can be improved, especially the local wind pressure in the corners, edges and roof ridges of low buildings can be improved obviously. The main work of this paper is as follows: 1. CFD detailed numerical simulation technology based on rans is used to study the windshield performance of trees to low buildings. Based on the measured data of TTU model, the setting of parameters in numerical simulation is studied, including calculation domain size, minimum mesh size, turbulence model selection, boundary condition setting and discrete solution algorithm of governing equation, etc. In order to improve the accuracy of CFD numerical simulation. 2. Numerical simulation of tree windshield performance. The numerical simulation method of tree windshield performance is established by using the additional source term method of porous media simulation. The validity of the numerical model is verified by comparing with the measured data. By changing the tree crown thinness, tree height, crown shape and tree spacing, the wind field characteristics of the downstream trees are studied, and the distribution characteristics of wind pressure and wind speed under different operating conditions are given. The variation of wind velocity in the lower reaches of trees is described by the velocity distribution curve. The results show that the crown thinning rate and tree height are the main factors affecting the downstream flow field. The tree parameters such as crown thinness, tree height, tree crown shape, roof slope angle, cornice shape and the distance between trees and houses were studied. The influence of trees on the wind pressure of low buildings was obtained. Based on the above research, the characteristics of wind speed and pressure distribution around the building are given, and the variation trend of the wind pressure in the low house under different working conditions is analyzed, which provides a theoretical reference and suggestions for enhancing the wind resistance of the low house.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU352.2

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