Three-Dimensional Water Temperature and Hydrodynamic Simulation of Xiangxi River Estuary

2013 ◽  
Vol 726-731 ◽  
pp. 3212-3221 ◽  
Author(s):  
Wei Ping Yin ◽  
Dao Bin Ji ◽  
Nian San Hu ◽  
Tao Xie ◽  
Yu Ling Huang ◽  
...  

When the impoundment of the Three Gorges Reservoir begins, the water level rises, and the water flow rate slows down, thus the residence time of bay and tributary pollutant extends, and the water environment changes significantly, resulting in different degrees of cyanobacteria outbreak in each spring. Numerous studies show that nutrient concentrations in mainstream is relatively higher than in tributary, so stratified density current of mainstreams and tributaries has played a key role on Bay eutrophication. In order to investigate the exchange process of mainstreams and tributaries, set boundary conditions according to the observed data, and then simulate Xiangxi estuary three-dimensional hydrodynamic characteristics by using Flow-3D software, which can simulate it well. The model theoretically confirms that the intrusion density current phenomenon does exist in typical tributaries, and the simulation results show that near the estuary region, there is a big diversity in the temperature field and the flow field along the transverse distribution, but when the estuary distance increases, the flow field in the cross section, except for a small area near the riverbank, tends to be in a mean state along the transverse distribution.

2018 ◽  
Vol 5 (5) ◽  
pp. 171255 ◽  
Author(s):  
Cheng-Lin Liu ◽  
Ze Sun ◽  
Gui-Min Lu ◽  
Jian-Guo Yu

Gas-evolving vertical electrode system is a typical electrochemical industrial reactor. Gas bubbles are released from the surfaces of the anode and affect the electrolyte flow pattern and even the cell performance. In the current work, the hydrodynamics induced by the air bubbles in a cold model was experimentally and numerically investigated. Particle image velocimetry and volumetric three-component velocimetry techniques were applied to experimentally visualize the hydrodynamics characteristics and flow fields in a two-dimensional (2D) plane and a three-dimensional (3D) space, respectively. Measurements were performed at different gas rates. Furthermore, the corresponding mathematical model was developed under identical conditions for the qualitative and quantitative analyses. The experimental measurements were compared with the numerical results based on the mathematical model. The study of the time-averaged flow field, three velocity components, instantaneous velocity and turbulent intensity indicate that the numerical model qualitatively reproduces liquid motion. The 3D model predictions capture the flow behaviour more accurately than the 2D model in this study.


2013 ◽  
Vol 353-356 ◽  
pp. 2567-2571 ◽  
Author(s):  
Zhen Zhen Yu ◽  
Ling Ling Wang ◽  
Lei Zhang ◽  
Yu Xia Yang ◽  
Li Yan ◽  
...  

The heat changes and distribution in water body provide one of the most important elements of structure influencing a host of chemical and biological processes. After the river-type reservoir was constructed, backwater entered into some tributaries, resulting in slow flow velocities in these tributaries. This paper made a reasonable description on the physical mechanism of hydrodynamic and water temperature distributions in a typical tributary bay, basing the hydrodynamic & water temperature coupled three-dimensional mathematical model. Through a large number of measured hydrologic, temperature and meteorological data, the paper simulated and obtained the hydrodynamic and water temperature distribution structure of the typical tributary bay and its evolution process, and described the hydrodynamic characteristics with precise values during the raising and falling temperature period; it is shown from the results that velocity vectors change displayed the water flow moved in a two-way circulation due to non-equilibrium warming and cooling on riverway cross-section, and the maximum flow velocity, turbulent kinetic energy and vorticity appeared on the surface water body, as well as wall near the tributary bay, and the turbulent kinetic energy is minimum on the center of tributary bay. The simulation experiment accurately captured the circulation phenomena caused by temperature difference, and proposed detailed distributions of flow field and related turbulent physical quantity, showed the strong coupling of flow field and temperature field change.


Author(s):  
Eric Savory ◽  
Norman Toy ◽  
Shiki Okamoto ◽  
Yoko Yamanishi

2017 ◽  
Author(s):  
Adnan Ismael ◽  
Hamid Hussein ◽  
Mohammed Tareq ◽  
Mustafa Gunal

2009 ◽  
Vol 24 (3) ◽  
pp. 342-350 ◽  
Author(s):  
Ali Vakil ◽  
Arash Olyaei ◽  
Sheldon I. Green

1991 ◽  
Vol 24 (6) ◽  
pp. 171-177 ◽  
Author(s):  
Zeng Fantang ◽  
Xu Zhencheng ◽  
Chen Xiancheng

A real-time mathematical model for three-dimensional tidal flow and water quality is presented in this paper. A control-volume-based difference method and a “power interpolation distribution” advocated by Patankar (1984) have been employed, and a concept of “separating the top-layer water” has been developed to solve the movable boundary problem. The model is unconditionally stable and convergent. Practical application of the model is illustrated by an example for the Pearl River Estuary.


1998 ◽  
Vol 120 (4) ◽  
pp. 840-857 ◽  
Author(s):  
M. P. Dyko ◽  
K. Vafai

A heightened awareness of the importance of natural convective cooling as a driving factor in design and thermal management of aircraft braking systems has emerged in recent years. As a result, increased attention is being devoted to understanding the buoyancy-driven flow and heat transfer occurring within the complex air passageways formed by the wheel and brake components, including the interaction of the internal and external flow fields. Through application of contemporary computational methods in conjunction with thorough experimentation, robust numerical simulations of these three-dimensional processes have been developed and validated. This has provided insight into the fundamental physical mechanisms underlying the flow and yielded the tools necessary for efficient optimization of the cooling process to improve overall thermal performance. In the present work, a brief overview of aircraft brake thermal considerations and formulation of the convection cooling problem are provided. This is followed by a review of studies of natural convection within closed and open-ended annuli and the closely related investigation of inboard and outboard subdomains of the braking system. Relevant studies of natural convection in open rectangular cavities are also discussed. Both experimental and numerical results obtained to date are addressed, with emphasis given to the characteristics of the flow field and the effects of changes in geometric parameters on flow and heat transfer. Findings of a concurrent numerical and experimental investigation of natural convection within the wheel and brake assembly are presented. These results provide, for the first time, a description of the three-dimensional aircraft braking system cooling flow field.


Sign in / Sign up

Export Citation Format

Share Document