Analysis of front of density underflow by the turbulence model

湍流模型对密度底流前沿的分析

• 批准号: 02650355
• 负责人: FUKUSHIMA Yusuke
• 金额: $ 1.6万
• 依托单位: Nagaoka University of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1990
• 资助国家: 日本
• 起止时间: 1990 至 1991
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-02650355/
• 关键词: Density underflow; Density front; Turbulence model; Numerical analysis; 下層密度流; フロント

The purpose of this study is to analyze the front of density underflow using the k-epsilon turbulence model. First, in order to investigate the turbulence structure of the front of the density underflow and the mechanism of the entrainment by the front, the experiments are carried out. The angle of the bed slope is chosen as a parameter. The salt water flows into the body of the fresh water filled in the tank to form the density front. The velocity distributions in the density front are measured by the hydrogen bubble method. The concentration distributions of salinity in the front are measured by the conductivity meter. From these experiments, the properties of the distributions of the velocity and the concentration in the density front are clarified in comparison with the characteristics of the steady region of the density underflow.Next, the method of the unsteady numerical analysis using k-epsilon turbulence model is developed. The model consists of the following basic equations : … More the mass conservation equation of the fresh water, the conservation equation of the salinity concentration, the momentum equation, the equation of the kinetic energy of turbulence and the equation of the viscous dissipation rate of the turbulence. The numerical analysis model adopts the volume integral method to discretize the basic equations. This method is numerically stable in comparison with the other method.The preliminary calculations are carried out to test the present model of the numerical analysis. The target of the calculation is the steady region of the density underflow. The results are compared with the experimental data. The present model explains well the characteristics of velocity and concentration distributions of the density underflow.The present model is applied to the analysis of the front of the density underflow in which the flow is essentially unsteady. The distributions of the velocity and concentration of the aslinity and the interface of the density front are calculated. The flow mechanism of the unsteady density front is explained well by the present analysis. Less

本研究的目的是利用k-ε紊流模型分析密度底流前缘。首先，为了研究稠密底流前缘的湍流结构及其卷吸机理，进行了实验研究。床面坡度的角度被选为参数。盐水流入水箱中的淡水体中，形成密度锋。用氢气泡法测量了密度阵面的速度分布。用电导率仪测量了锋面盐度的浓度分布。通过与密度底流定常区特性的比较，阐明了密度前缘区的速度和浓度分布特性。其次，发展了采用k-ε湍流模型的非定常数值分析方法。该模型由以下基本方程组成： ...更多信息 淡水质量守恒方程、盐度守恒方程、动量方程、湍流动能方程和湍流粘性耗散率方程。数值分析模型采用体积积分法对基本方程进行离散。与其它方法相比，该方法具有数值稳定性好的特点，并进行了初步计算，以检验本文的数值分析模型。计算的目标是密度底流的稳定区域。计算结果与实验数据进行了比较。该模型较好地反映了密度底流的速度和浓度分布特征，并可用于分析非定常流动的密度底流前缘。计算了倾斜面和密度锋界面的速度和浓度分布。本文的分析很好地解释了非定常密度阵面的流动机理。少

项目成果

福嶋 祐介,早川 典生,加納 仙一: "下層密度流フロントの流動機構に関する研究" 第46回年次学術講演会講演概要集、土木学会. 46. 698-699 (1991)

Yusuke Fukushima，Norio Hayakawa，Senichi Kano：“低密度流动前沿的流动机制研究”第46届学术会议摘要，日本土木工程师学会46。698-699（1991）。

渡邊 政美,福嶋 祐介: "kーε乱流モデルによる下層密度流の数値解析" 第45回年次学術講演会講演概要集、土木学会. 45. 452-453 (1990)

Masami Watanabe、Yusuke Fukushima：“使用 k-epsilon 湍流模型对低密度流进行数值分析”第 45 届学术会议摘要，日本土木工程师学会 45. 452-453 (1990)。

Fukushima,Y.and M.Watanabe: "Numerical Simulation of density under flow" Journal of Hydroscience and Hydraulic Engineering. 8ー1. 31-40 (1990)

Fukushima, Y. 和 M. Watanabe：“流动下密度的数值模拟”水科学与水利工程学报 8-1（1990）。

Fukushima,Y.and M.Watanabe: "Numerical Simulation of density under flow" Journal of Hydroscience and Hydraulic Engineering. 8-1. 31-40 (1990)

Fukushima，Y. 和 M.Watanabe：“流动下密度的数值模拟”水科学与水利工程学杂志。

Kanoh, S., Fukushima, Y. and Hayakawa, N.: "Flow mechanism of two-dimensional front of density underflow" Proc. Annual Meeting of Niigata Branch of Japan Society of Civil Engineers. 8. 58-62 (1991)

Kanoh, S.、Fukushima, Y. 和 Hayakawa, N.：“密度底流二维前沿的流动机制”Proc。