Construction of Flood Flows Simulation Model Based on High Resolution Upwinding Finite Difference Method

基于高分辨率逆风有限差分法的洪水模拟模型构建

• 批准号: 11450190
• 负责人: AKIYAMA Junichiro
• 金额: $ 6.46万
• 依托单位: Kyushu Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-11450190/
• 关键词: Flood Flow Simulation; Flux-Difference Splitting; Finite-Volume Method; Unstructured Grid System; Dam Break Flow; Hydrodynamic Force; Laboratory Experiment; PTV

A first-order accurate numerical model- based on Flux-Difference Splitting (FDS) technique and unstructured Finite-Volume Method(FVM) for 2D Flood Flows (FUF-2DF Model) is newly constructed. The model uses unstructured triangular grid system and Incorporates conservative properties as well as signal propagation through FDS technique. A SA- FUF-2DF Model, which is essentially a spatially averaged FUF-2DF Model, is also developed. The FUF-2DF Model is designed to be appled to such larger elements existing In a flood plain than a grid size as buildings and others, while the GA-FUF-2DF Model is designed to treat such smaller elements than a grid size as trees, small houses and others existing within a grid. In the GA-FUF-2DF Model , the forces acting from elements on a flow are evaluated as reaction forces.For comprehensive verification of the model, experiments on two-dimensional dam-break flood waves propagating in a channel as well as a floodplain in presence of submerged and/or unsubme … More rged larage structures and/or small elements are conducted. A new methods to obtain the depths and the surface velocities of flood flows propagating on a flood plain In dry-bed condition have been developed: the depths and the surface velocities of flood flows are measured by using the Image analysis by a computer and Particle Tracking Velocimetry(PTV), respectively. The model verifications against these experimental data show that the proposed model can reproduce flood flows with structures with reasonable accuracy.A new numerical model for free-surface flow simulations Is constructed; first and second-order flux-difference splitting schemes are combined with the Preissmann slot to simulate flows in a closed conduit, wherein the flow may change from free-surface to pressurized flow and vice versa. The models can simulate conduits with uniform cross-sections of arbitrary shape as well as with bed slope and bed friction. The models are verified with available experimental data on free-surface-pressurized flows for pipes and rectangular conduits. Thereafter, the models are tested against some exacting sample problems. It Is demonstrated that the models yield very reasonable results In all the cases considered. A sensitivity analysis Is performed for the size of the slot and useful conclusions are drawn from the study for the simulation of free-surface pressurized flows.Hydrodynamic force exerting on a squre pillar placed In steady or unsteady free surface shear flows were Investigated experimentally. In steady flows, It is found that the drag coefficients of a squre pillar at a given 'a decreases with B/d in the range of B/d=3〜14 and is constant when B/d≧14, and that the values of Cd in a shear flow are different from those in uniform flow. Diagrams to describe the relationships between Cd and α as well as Cd and B/d are presented. In unsteady flows, It Is found that the ratio of surface to depth-averaged velocity is about 1.12. The magnitude of Cd of the pillar 1D dam break flows Is compared with that of steady uniform flows, and increases very slowly with t* after t*>70. Less

基于流差分裂（FDS）技术和非结构网格体积法（FVM），建立了一个一阶精度的二维洪水数值模型（FUF-2DF模型）。该模型采用非结构化三角形网格系统，并通过FDS技术来描述保守性以及信号传播。本文还发展了一个SA-FUF-2DF模式，它实质上是一个空间平均的FUF-2DF模式. FUF-2DF模型适用于河漫滩中比网格尺寸大的建筑物等要素，而GA-FUF-2DF模型适用于比网格尺寸小的树木、小型房屋等要素。在GA-FUF-2DF模型中，单元对水流的作用力作为反作用力来计算。为了对模型进行全面的验证，本文进行了二维溃坝洪水波在河道和漫滩中传播的淹没和未淹没试验，并对模型进行了数值模拟 ...更多信息 引导有规则的大尺寸结构和/或小元件。本文提出了一种测量洪泛区干床条件下洪水流深度和表面流速的新方法：分别用计算机图象分析法和粒子跟踪测速法（PTV）测量洪水流的深度和表面流速。建立了一种新的自由面水流数值模拟模型，将一阶和二阶通量差分分裂格式与Preissmann槽相结合，模拟了封闭管道中自由面和有压面之间的流动。该模型可以模拟具有任意形状的均匀横截面以及河床坡度和河床摩擦的管道。该模型进行了验证与现有的实验数据的自由表面加压流动的管道和矩形管道。此后，模型进行了测试，对一些严格的样本问题。它表明，模型产生非常合理的结果在所有的情况下考虑。本文还对切缝尺寸进行了敏感性分析，得出了对自由面有压流动模拟有用的结论。本文对定常和非定常自由面剪切流中方柱所受的水动力进行了实验研究。在定常流动中，当B/d=3 × 14时，方柱的阻力系数随B/d的增大而减小，当B/d ≥ 14时，方柱的阻力系数基本不变。给出了Cd与α、Cd与B/d的关系图。在非定常流中，表面平均流速与深度平均流速之比约为1.12。柱体一维溃坝流的Cd值与恒定均匀流的Cd值相比，t*>70以后，Cd随t* 的增加非常缓慢。少

项目成果

J. Akiyama, M. Ura, M. Shigeeda and Y. Arita: "Numerical model for 2-D transient free surface flows with obstructions"J. of Hydroscience and Hydraulic Engineering, JSCE. Vol.18,No.1. 85-95 (2000)

J. Akiyama、M. Ura、M. Shigeeda 和 Y. Arita：“有障碍物的二维瞬态自由表面流的数值模型”J.

秋山壽一郎、浦 勝、重枝未玲、ジャー: "1次元浅水流方程式のFDSに基づく数値解析法"水工学論文集. 第44巻. 473-478 (2000)

Juichiro Akiyama，Masaru Ura，Mirei Shigeta，Jah：“一维浅水流方程的数值分析方法”水利工程学报第44卷473-478（2000）。

A.K. Jha, J. Akiyama and M. Ura: "FDS and FVM schemes for 2-D flood flow simulations"J. of Hydroscience and Hydraulic Engineering, JSCE. Vol.18,No.1. 73-84 (2000)

A.K.

J. Akiyama, M. Shigeeda, T. Kobayashi and K. Oota: "Hydrodynamic force exerting on a squre pillar in unsteady free surface flows"Annual Journal of Hydraulic Engineering. Vol.46. 1205-1210 (2002)

J. Akiyama、M. Shigeeda、T. Kobayashi 和 K. Oota：“不稳定自由表面流中施加在方柱上的水动力”水利工程学年刊。

重枝未玲,秋山壽一郎: "非構造格子を用いた有限体積法に基づく平面2次元洪水流数値モデル"水工学論文集. 第45巻. 895-900 (2001)

Mirei Shigeta、Juichiro Akiyama：“基于非结构化网格的有限体积法的平面二维数值洪水流模型”水利工程学报第 45 卷 895-900 (2001)。