The central problem of the lattice Boltzmann method （LBM） is to construct a discrete equilibrium. In this paper, a multi-speed 1D cell-model of Boltzmann equation is proposed, in which the cell-population equilibriu...The central problem of the lattice Boltzmann method （LBM） is to construct a discrete equilibrium. In this paper, a multi-speed 1D cell-model of Boltzmann equation is proposed, in which the cell-population equilibrium, a direct non- negative approximation to the continuous Maxwellian distribution, plays an important part. By applying the explicit one-order Chapman-Enskog distribution, the model reduces the transportation and collision, two basic evolution steps in LBM, to the transportation of the non-equilibrium distribution. Furthermore, 1D dam-break problem is performed and the numerical results agree well with the analytic solutions.展开更多
The Tangjiashan landslide dam failed on June 10, 2008, which was the largest one formed during the Wenchuan earthquake in China. No human lives were lost in this dam failure. This paper presents a description of the d...The Tangjiashan landslide dam failed on June 10, 2008, which was the largest one formed during the Wenchuan earthquake in China. No human lives were lost in this dam failure. This paper presents a description of the dam, including the dam geometry, the hydrograph and the reservoir capacity, the diversion channel and the drainage from the lake. Several empirical models are applied to predict the breach parameters, the peak outflows and the reservoir volumes during this breach event. The main objective of the study is to compare various prediction models and to make recommendation of the best model for the prediction of the breach width, the failure time, and the peak outflow. The breach widths predicted by the Froehlich methods with considerations of the reservoir storages and the effect of failure mode are considered to be more reasonable. All prediction methods discussed in this paper are found to underestimate the breach formation time due to the complex material and the large thickness of the dam. The results from the soil conservation services（SCS） method compare well with the observed peak outflow. The Marone method in combination with the coefficient expressions proposed by Macchione gives excellent results in the simulation of the reservoir volume-level curve.展开更多
基金Project supported by the National Natural Science Foundation of China(5137912551490675+3 种基金114320095157914511272120)the Chang Jiang Scholars Program of China(T2014099)~~
基金Project supported by the National Natural Science Foundation of China (Grant Nos 70271069 and 60773195)
文摘The central problem of the lattice Boltzmann method （LBM） is to construct a discrete equilibrium. In this paper, a multi-speed 1D cell-model of Boltzmann equation is proposed, in which the cell-population equilibrium, a direct non- negative approximation to the continuous Maxwellian distribution, plays an important part. By applying the explicit one-order Chapman-Enskog distribution, the model reduces the transportation and collision, two basic evolution steps in LBM, to the transportation of the non-equilibrium distribution. Furthermore, 1D dam-break problem is performed and the numerical results agree well with the analytic solutions.
文摘1998～2000年,欧盟资助了一项称为CADAM(Concerted Actionon Dambreak Modelling)的所谓溃坝模拟协调行动计划,拟对当时所使用的方法及其在模拟和预报溃坝方面的应用加以研究。针对CADAM项目研究中提炼出来的一些关键技术问题,"IMPACT"欧洲合作工程项目对其展开了研究,IMPACT是CADAM项目的延续。IMPACT(Investigation of ExtreMe Flood Processes And UnCertainTy)项目意为特大洪水过程及其不确定性的研究。主要介绍CADAM项目得出的主要结论和对IMPACT项目进行简要介绍。
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51209155,51109149)the Research Fund for the Doctoral Program of Higher Education of China(Grant No.20110181120093)
文摘The Tangjiashan landslide dam failed on June 10, 2008, which was the largest one formed during the Wenchuan earthquake in China. No human lives were lost in this dam failure. This paper presents a description of the dam, including the dam geometry, the hydrograph and the reservoir capacity, the diversion channel and the drainage from the lake. Several empirical models are applied to predict the breach parameters, the peak outflows and the reservoir volumes during this breach event. The main objective of the study is to compare various prediction models and to make recommendation of the best model for the prediction of the breach width, the failure time, and the peak outflow. The breach widths predicted by the Froehlich methods with considerations of the reservoir storages and the effect of failure mode are considered to be more reasonable. All prediction methods discussed in this paper are found to underestimate the breach formation time due to the complex material and the large thickness of the dam. The results from the soil conservation services（SCS） method compare well with the observed peak outflow. The Marone method in combination with the coefficient expressions proposed by Macchione gives excellent results in the simulation of the reservoir volume-level curve.
