QQ客服 官方微博 反馈留言

题名	基于数值模拟的交错齿槛型排导槽的优化研究
作者	张钰
学位类别	硕士
答辩日期	2014
授予单位	中国科学院研究生院
授予地点	北京
导师	陈晓清
关键词	排导槽 交错齿槛 试验 数值模拟 优化研究
其他题名	Study on Optimization of Drainage Cannal with Indented-sill For Debris Flow based on Numerical Simulation
学位专业	建筑与土木工程
中文摘要	泥石流排导槽是一类应用于流域中下游堆积区的灾害防治工程，目前效果较好的有全衬砌“V”型槽和具备软基消能特性的“东川”槽。交错齿槛槽在“东川”槽肋槛的基础上，结合水利工程中丁坝的导流护坡功能，在槽底基础上布置交错型齿槛，达到软基消能、调节泥石流在槽内的流速和流态，同时有较高的排泄效能的目的。交错齿槛型泥石流排导槽最大的特征是齿槛结构的交错排布，改变槽内的表面形态特征，从而增加排导槽的糙率系数，达到减速消能的目的。交错槽中齿槛的基本参数很多，如何选取齿槛高度、间距、夹角、长度等参数，使其达到良好的排泄效果，是目前急需解决的问题。本研究重点关注齿槛的间距L、夹角α两个参数，通过水槽试验和数值模拟，分析了泥石流在交错槽中的综合糙率系数和齿槛参数对排导槽特征的影响规律。并在此基础上，进行交错齿槛型泥石流排导槽的优化设计。通过水槽定床试验，观测不同容重泥石流在交错槽中的运动特征，分析计算交错槽综合糙率的变化范围及趋势。根据计算分析，稀性泥石流在槽内的综合糙率比粘性泥石流高，变化范围大：稀性泥石流在交错槽中翻滚前进，能量耗散剧烈，糙率取值范围为0.02~0.051；粘性泥石流在交错槽中为层流状，整体流动，能量耗散相对较小，糙率取值范围为0.008~0.038。数值模拟方面，以粘性泥石流为例，采用Bingham流体模型模拟不同工况下泥石流的运动情况，探讨交错齿槛型排导槽的减速消能效果，得出以下主要结论： ①交错槽的适用范围流深较小且比降较小（≤10%）时，交错齿槛对泥石流流速的调节效果明显，因此交错槽交错槽适宜于宽阔型且主沟纵比降小的沟道，这种地形有条件布置宽槽，这样泥石流进入排导槽不易形成较大流深，交错齿槛能发挥其减速消能的作用。 ②齿槛夹角α的影响齿槛夹角对交错槽内泥石流流体压强的分布影响较小，对流速的调节有一定影响： i=5%时，齿槛角度为45°~80°流速均较为恒定，齿槛的减速效果明显；i=10%时，齿槛角度为45°、70°时泥石流在槽内速度较为恒定，为较优选择；i=15%时，齿槛的调速作用减弱，不同角度下，泥石流均在槽内做加速运动，但齿槛角度α=45°时，加速现象较弱。 ③齿槛间距L的影响齿槛间距为交错槽内泥石流流速的调节效果明显：i=5%时，间距L为8~10m（1D ~ 1.25D）时齿槛的调速速效果明显；i=10%时，间距L为8m（1D）时齿槛的调速效果明显；i=15%时，泥石流均在槽内做加速运动，但间距L为6m（0.75D）时加速效果较弱，为较为优化设置。本文通过水槽试验和数值模拟研究了交错槽的排导特征，得到泥石流在交错槽内运动基本特征，并由此对交错槽进行优化设计，提出了优化方案，取得初步成果。
英文摘要	Drainage canal is one disaster countermeasure used in debris flow fans, including the "V" shape debris flow drainage canal and ladder shape debris flow drainage canal. The debris flow drainage canal with indented-sill is prominent in: (1) protection to the base of canal. (2) Lows the velocity and regulates the flow regime. (3) High transport rate. The largest feature for drainage canal with indented-sill is interveined arrangement of the tooth sill structure so that it can change the surface of drainage chanel,which can increase the roughness coefficient, to reach an effect of slowing down and dissipating energy of debris flow.Because drainage canal with indented-sill has a lot of basic parameter,so how to determine the value of parameters,such as the height of sills,the distance of sills, the angle between sills and wall, and the length of the sills,is the main problem which needs to be sloved right now if you want to get a good effect of discharging of the debris flow.During my research in this paper, with flume experiments and numerical simulations, I mainly focus on the distance and the angle of sills to analyze how the synthetic roughness coefficient and parameters of sills to influence the features of drainage canal.I will also optimize the design of drainage canal with indented-sill under the above research. With the flume experiment, I have got the motion features of different density in the drainage canal with indented-sill, caculated and analyzed the range and trend of the synthetic roughness coefficient.Through the dissipating feature of debris flow under different parameters of sills, I have found that the energy loss of dilute debris flow was more than the viscous one, so it also meant that the synthetic roughness coefficient of dilute debris flow was higher and had a larger range than the viscous one.In the aspect of numerical simulations, such as the viscous debris flow, I have taken the Bingham fluid model to simulate motion conditions of debris flow under different types ,which was used to study the effect of slowing down and dissipating energy of drainage canal with indented-sill and pionted out the applied scope of drainage canal with indented-sill.
语种	中文
公开日期	2015-02-26
内容类型	学位论文
源URL	[http://ir.imde.ac.cn/handle/131551/7830]
专题	成都山地灾害与环境研究所_山地灾害与地表过程重点实验室
推荐引用方式 GB/T 7714	张钰. 基于数值模拟的交错齿槛型排导槽的优化研究[D]. 北京. 中国科学院研究生院. 2014.

个性服务

查看访问统计

相关权益政策

暂无数据

收藏/分享

除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。