复杂地形桥位风场实测与CFD数值模拟

发布时间：2018-02-11 17:58

本文关键词： 复杂地形风场实测计算流体动力学数值模拟平均风特性脉动风特性　出处：《湖南大学》2015年硕士论文　论文类型：学位论文

【摘要】：桥位风特性参数确定是大跨度桥梁抗风设计中十分重要的问题之一,对合理确定大桥设计风荷载和评估大桥抗风性能具有至关重要的影响。复杂地形桥位由于地形差别较大,其桥位风特性参数变化较为复杂,近年来复杂地形桥位风特性的研究逐渐成为桥梁工程研究领域的热点问题之一。本文以拟建的山西临猗黄河大桥工程为依托,分别采用现场实测与计算流体动力学方法(Computational Fluid Dynamics,CFD)进行研究。论文主要研究工作如下:1.在综述国内外复杂地形桥位风场实测与CFD数值模拟研究现状的基础上,以拟建的山西临猗黄河大桥为依托,制定了本文的研究内容与技术路线。2.简要介绍了山西临猗黄河大桥工程,详细介绍了复杂地形桥位风实测方案,如风观测塔、风速仪、数据采集、传输系统等,并对风速仪精度检验和风观测系统的运行情况做了简要介绍。3.简要介绍了桥位风实测数据的处理方法,在此基础上基于MATLAB编写了桥位实测数据处理程序。分别对观测期内的平均风速和脉动风速进行了处理,得到了相应的风特性参数,平均风特性包括:风速、风向以及风剖面;脉动风特性包括:湍流度、阵风因子、湍流积分尺度以及脉动风功率谱密度等。观测期间风观测塔80m高度处极大风速为23.1m/s,最大风速为18.3 m/s;主导风向为北风偏东;风剖面指数为??1670.0,与B类地表向接近;实测脉动风谱与规范给出的风谱吻合较好。4.在简要介绍CFD的基础上,首先进行了单峰山丘风场数值模拟,即分别采用RNG k-?和SST k-?湍流模型对单峰山丘风场进行了数值模拟;然后针对拟建的临猗黄河大桥桥位地形进行风场数值模拟,分别比较了近地层网格厚度、网格分辨率对模拟结果的影响。最后,对该桥位地形分别进行了四个工况的风场CFD数值模拟,得到了相应工况的风速分布规律。
[Abstract]:The determination of wind characteristic parameters is one of the most important problems in the wind-resistant design of long-span bridges. It is of great importance to reasonably determine the wind loads and evaluate the wind-resistant performance of the bridges. In recent years, the study on the wind characteristics of the bridge with complex topography has gradually become one of the hot issues in the field of bridge engineering. This paper relies on the proposed project of Linyi Yellow River Bridge in Shanxi Province. The field measurement and computational fluid dynamics (CFD) methods are used to carry out the research. The main research work of this paper is as follows: 1. On the basis of summarizing the present situation of wind field measurement and CFD numerical simulation at bridge site of complex terrain at home and abroad, Based on the proposed Linyi Yellow River Bridge in Shanxi Province, the research content and technical route of this paper are formulated. 2. The project of Linyi Yellow River Bridge in Shanxi Province is briefly introduced, and the wind measurement scheme at the bridge location of complex terrain is introduced in detail, such as wind observation tower, anemometer, etc. Data acquisition, transmission system, and anemometer precision test and wind observation system operation are briefly introduced. 3. The processing method of bridge wind measured data is briefly introduced. On this basis, the data processing program of bridge site is compiled based on MATLAB. The average wind speed and pulsating wind speed during the observation period are processed, and the corresponding wind characteristic parameters are obtained. The average wind characteristics include: wind speed, wind direction and wind profile; The characteristics of pulsating wind include turbulence degree, gust factor, integral scale of turbulence and power spectral density of pulsating wind. During the observation period, the maximum wind speed at 80m height of the wind observation tower is 23.1m / s, the maximum wind speed is 18.3 m / s, the dominant wind direction is east-north wind, and the wind profile index is? ? The measured pulsating wind spectrum is in good agreement with the wind spectrum given by the code. (4) on the basis of a brief introduction of CFD, the numerical simulation of the wind field of a single peak hill is carried out, i.e., the RNG k-? And SST k-? The wind field of single peak hill is numerically simulated by turbulence model, and then the wind field is numerically simulated in view of the proposed bridge of Linyi Yellow River Bridge, and the influence of the thickness of near-ground grid and the resolution of grid on the simulation results are compared respectively. The CFD numerical simulation of the wind field of the bridge is carried out under four working conditions, and the wind velocity distribution law of the corresponding conditions is obtained.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U442.59

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