Development of Reasonable Numerical Methods For Predicting Complicated Hydraulic Appearance With Different Time and Space Scales

发展合理的数值方法来预测不同时间和空间尺度的复杂水力形态

• 批准号: 08456116
• 负责人: SHIMADA Masashi
• 金额: $ 5.06万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08456116/
• 关键词: Open Channels; Compound Cross Section; Water Surface Analysis; Vegetation Zones; Pipelines; Combined Method Using Time-line Interpolations; Water Hammer; Grid Designs; 1次元流れ; 特性直線法; 時間補間; 誤差解析; 境界; ループ

(1)The numerical methods are discussed theoretically and experimentally developed for predicting water surface of one dimensionally varied steady flows in open channels with a regular cross-section and locally varied resistance zone near the one-sided wall. The resistance zone is composed of pile series arranged like vegetation belt or rough stone zone. The lateral distribution of depth-averaged velocity within a cross section is firstly estimated from the equation of motion including the eddy diffusion effects due to interaction between distributed piles. The longitudinal water level is calculated using the one-dimensional energy equation in which the resistance effect of the pile zone is estimated as the lateral velocity distribution. The comparisons between the experimental and calculated values with respect to the velocities and water levels are very good to examine the usefulness of the analyses. The similar method is extended to the channels with compound sections. With that meth … More od, the cross sections of the flow were divided into three regions to predict the distribution of velocity and water level. With the previous methods the lateral velocity distribution assumes the uniform flow condition while we assume non-uniform flows. The longitudinal water level can be predicted by using the lateral velocity distribution and the energy slope obtained from that velocity distribution. The calculation method is validated by comparisons of the results obtained from the experiments made in the channels with regular and compound sections under the conditions of several kinds of pile zones.(2) To design reasonably grids for slow and rapid transient analysis using the method of characteristics is required to estimate the errors due to the discretizations and lime-line interpolations. The discretization errors for the linear valve closure problems in the simple piping systems is numerically and theoretically investigated with respect to pressure head rises, and formulated as the non-dimensional semi-theoretic equation, which is a function of the time scale of waves(valve closure time), pipe length, wavespeeds, number of pipes, and frictional coefficients. The combined time-line method for slow and rapid transient analysis is offered through designing adequate time-step sizes and grids, which satisfy the criteria for the discretization error and the error du to time-line interpolations. It is examined by numerical computations of transients using the pipeline model. Less

(1)从理论上和实验上讨论了一维变化稳定流的水面预测方法，该方法具有规则截面和局部变化阻力区的明渠靠近单侧壁面。阻力区由像植被带或粗石带一样排列的桩系组成。首先根据考虑分布桩间相互作用引起的涡流扩散效应的运动方程，估计了截面内深度平均速度的横向分布。纵向水位计算采用一维能量方程，其中桩区阻力效应估计为横向速度分布。关于流速和水位的实验值和计算值之间的比较很好地检验了分析的有效性。将类似的方法推广到具有复合断面的河道。利用该方法，将水流的横截面划分为三个区域，以预测流速和水位的分布。在以往的方法中，横向速度分布假设匀速流动，而我们假设非匀速流动。利用横向速度分布和由横向速度分布得到的能量斜率可以预测纵向水位。通过对规则断面和复合断面河道在几种桩区条件下的试验结果进行对比，验证了计算方法的正确性。(2)利用特征法设计合理的网格进行慢速和快速瞬态分析，需要估计离散化和线插值引起的误差。本文从数值和理论上研究了简单管道系统中线性阀门关闭问题的离散化误差与压力水头上升的关系，并将其表述为波浪（阀门关闭时间）、管道长度、波速、管道数和摩擦系数等时间尺度的无量纲半理论方程。通过设计适当的时间步长和网格，满足离散化误差和时间线插值误差的要求，提出了慢速和快速瞬态分析的时间线结合方法。利用管道模型进行了瞬态数值计算。少

项目成果

Kinose, K., N.Mori, & M.Takahashi: "Analysis of Non-uniform Flow in Regular Cross-section Channel with Locally Varied Resistance Zone (In Japanese with english summary)" Trans.JSIDRE, (196). 41-48 (1998)

木之濑，K.，N.Mori，

Shimada, M: "Error Estimation of Time-Line Interpolations Used in Method of Characteristics for Waterhammer Analysis and Grid Design (In Japanese with english summary)" Trans.JSIDRE. (197). 1-8 (1998)

Shimada, M：“水锤分析和网格设计特征方法中使用的时间线插值的误差估计（日文，附英文摘要）” Trans.JSIDRE。

Shimada, M.: "Discretization Error and Grid Design in Method of Characteristics for Waterhammer Analysis (In Japanese with english summary)" Trans.JSIDRE. (198). 53-61 (1998)

Shimada, M.：“水锤分析特征方法中的离散化误差和网格设计（日文，附英文摘要）” Trans.JSIDRE。

SHIMADA,M.: "ADVANCES IN THEORY AND NUMERICAL TECHNIOUES ON TIME MARCHING APPROACH FOR STEADY FLOWS IN PIPELINE SYSTEMS" INT.CONF.ON PRESSURE SURGES AND FLUID TRANSIENTS. 523-535 (1996)

Shimada,M.：“管道系统中稳定流动的时间推进方法的理论和数值技术进展”关于压力波动和流体瞬变的 INT.CONF.。

木ノ瀬紘一、森 望: "抵抗体群によって流水抵抗が場所的に異なる単断面水路の不等流計算" 農業土木学会論文集. 196. 41-48 (1998)

Koichi Kinose、Nozomi Mori：“单个横截面渠道的不均匀流量计算，其中水流阻力因电阻器组而局部不同”，日本农业和土木工程师学会汇刊 196. 41-48 (1998)。