scholarly journals NUMERICAL MODEL OF CURRENT AND SEDIMENT TRANSPORT IN THE WAVE BOUNDARY LAYER

2011 ◽  
Vol 1 (32) ◽  
pp. 5
Author(s):  
Yuliang Zhu ◽  
Jing Ma ◽  
Hao Wang
Keyword(s):  
Boundary Layer ◽  
Mathematical Model ◽  
Eddy Viscosity ◽  
Sediment Concentration ◽  
Wave Boundary Layer ◽  
Time Invariant ◽  
Wave Boundary ◽  
The Mathematical Model ◽  
The Relationship ◽  
Turbulent Wave

Mathematical model is one of the means to study of turbulent wave boundary layer. The paper analysis of the existing model, adopt a more reasonable boundary condition to establish a improved mathematical model of 1DV turbulent wave boundary layer using k-ε model. The paper recommends brief flow simulation and mainly introduced the simulation of the sediment concentration. The paper use the eddy-viscosity value which calculation by the mathematical model and the model of You Zaijin on time-invariant eddy-viscosity into the relationship about sediment diffusion coefficient and eddy-viscosity to calculate the sediment concentration. The calculation results turns out the way that use the eddy-viscosity value which calculation by the mathematical model into the relationship can obtain better timely sediment concentration value. When use the model simulates the time-invariant sediment concentration, the two ways have not many distinctions. It means the way that that use the eddy-viscosity value which calculation by the mathematical model into the relationship is feasible.

The Improvement of k-ε Model in the Turbulent Wave Boundary Layer

2009 ◽  
Author(s):  
Yuliang Zhu ◽  
Jing Ma ◽  
Peipei Dong
Keyword(s):  
Boundary Layer ◽  
Eddy Viscosity ◽  
Wave Boundary Layer ◽  
Viscosity Models ◽  
Velocity Equation ◽  
Layer Flow ◽  
Wave Boundary ◽  
Advanced Model ◽  
Turbulent Wave ◽  
Empirical Constants

Numerical model is one of the means for investigating turbulent wave boundary layer. Many scholars have used various eddy-viscosity models to simulate wave turbulent boundary layer flow. On the basis of analyzing existing models, the article uses more reasonable boundary condition to establish an advanced model of turbulent wave boundary layer by k-ε model. Past models have two problems. Firstly, the calculation area is not united since one of the calculation areas is all-water depth and another is boundary layer thickness. Aimed at this problem, this model makes a sensitivity analysis of velocity and eddy-viscosity for various calculation area, which turns out that velocity inside the boundary layer is low-sensitive while the eddy-viscosity is high-sensitive to the change of calculation area. Secondly, a new integration adjust coefficient p is presented to solve the five empirical constants which are difficult to adjust in k-ε model. Although these five empirical constants have recommended value, the universality is not good. In order to obtain better eddy-viscosity value, many methods were suggested to get these five empirical constants, however, most are very complicated. In this article, adjust coefficient p is put before the diffusion item in the velocity equation, and p is a little bit smaller than 1. The result indicates that a reasonable eddy-viscosity can be easily adjusted using this method. The modified model has overcome some shortcomings of the previous models, and gets a better simulation effect.

scholarly journals Impact of Tide on Vertical Cu Transport in a River-Connected Lake

2018 ◽  
Author(s):  
Yeye Yang ◽  
Hua Wang ◽  
Huaiyu Yan ◽  
Dongfang Liang
Keyword(s):  
Mathematical Model ◽  
Geographical Location ◽  
Sediment Concentration ◽  
Average Concentration ◽  
Diurnal Tide ◽  
Desorption Process ◽  
Industrial Enterprises ◽  
Sediment Particles ◽  
The Mathematical Model ◽  
The Relationship

A typical river-connected lake, Jinshan Lake, was selected as the study area. By the combination of field experiment, laboratory experiment and mathematical model, we plotted the relationship between the concentration of DCu-SCu and FDI, and constructed the mathematical model of the migration and transformation of HMCu in Jinshan Lake. We choose a typical diurnal tide to simulate and revealed the vertical migration characteristics of HMCu in Jinshan Lake during a diurnal tide. The results show that: (1) The release rate of DCu was proportional to FDI and background content, respectively. (2) Due to the nearby industrial enterprises and terrain characteristics, SA loads the most HMCu, the average concentration is 70.07mg/kg. According to the characteristics and geographical location of LC, the concentration of copper in the two states fluctuates greatly (DCu: 43.20~74.77 mg/kg, SCu: 53.63~74.67mg/kg). The fluctuation trend of SCu in ZA is significantly different from that in other areas, which mainly due to the complex hydraulic distribution and the sorption-desorption process of HMs in sediment particles. The hydraulic disturbance of JG is the least and relatively stable, which is the farthest from the inlet of the lake and is the least affected by the Yangtze river. (3) The FDI in a diurnal tide reaches the suspension condition of fine sediment particles in each region. FDI and sediment concentration on the vertical exchange of two - state Cu is significant.

scholarly journals NON-UNIFORM SUSPENDED SEDIMENTS UNDER WAVES

1988 ◽  
Vol 1 (21) ◽  
pp. 84
Author(s):  
Aronne Armanini ◽  
Piero Ruol
Keyword(s):  
Experimental Data ◽  
Boundary Layer ◽  
Mathematical Model ◽  
Mathematical Formulation ◽  
Suspended Sediments ◽  
Two Dimensional ◽  
Different Diameters ◽  
Wave Boundary ◽  
The Mathematical Model ◽  
Dimensional Wave

An original mathematical formulation for suspended sediments in a two-dimensional wave boundary layer is presented. The model accounts for non-immediate adaptation of sediments to the hydrodinamic conditions, and allows to include the effect of sorting of the different diameters considered. The mathematical model is numerically solved through a finite difference scheme. It is suitable that results compare favourably with experimental data by Staub et alii.

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