scholarly journals Influence of water diversion on spatial and temporal distribution of flow field and total phosphorus (TP) concentration field in Taihu Lake

2020 ◽  
Vol 20 (3) ◽  
pp. 1059-1071 ◽  
Author(s):  
Ruichen Xu ◽  
Yong Pang ◽  
Zhibing Hu ◽  
Tianyi Zhu ◽  
John Paul Kaisam
Keyword(s):  
Flow Field ◽  
Taihu Lake ◽  
Concentration Field ◽  
Temporal Distribution ◽  
Water Diversion ◽  
Lake Area ◽  
Temporal And Spatial Distribution ◽  
Pearson Coefficient ◽  
East Lake ◽  
Influence Of Water

Abstract In order to evaluate the overall impact of water diversion on Taihu Lake, this paper carries out numerical simulation of the temporal and spatial distribution of the flow field and the TP concentration field in Taihu Lake based on measured data during the water diversion period by using the Euler–Lagrange method. The results show that: (1) the Pearson coefficient of monitoring points in the East Lake area increases significantly during the water diversion period, indicating that the diversion of water may indirectly influence water quality; (2) the diversion of water has a significant influence on the flow rate of the simulated stations in Taihu Lake, and the influence is Taipu (103%) > Gongwan (60%) >East Lake (31%); (3) when the amount of water flow transfer from the Wangyu River to the lake is greater than 100 m3/s, the mean concentration of TP in the Center and East lakes increases significantly (more than 50%). The recommended water diversion discharge is to be controlled in the range 100–200 m3/s and the total water diversion yield between 1.56 and 2.59 billion m3/a.

Hydrodynamics Simulation Study on Dian Lake Ecosystem

2011 ◽  
Vol 255-260 ◽  
pp. 2673-2680
Author(s):  
Hao Liang Cheng ◽  
Ju Rui Yang ◽  
Ji Min Hu ◽  
Zhen Ai Lu
Keyword(s):  
Water Quality ◽  
Flow Field ◽  
Concentration Field ◽  
Wetland Plants ◽  
Ecological Environment ◽  
Lake Ecosystem ◽  
Influence Of Water ◽  
Available Information ◽  
Lake Waters

Aiming at the eutrophication state of Dian Lake, based on hydrodynamics principle, and some available information about Dian Lake, such as eco-environmental construction planning, the previous work, and so on, a vertical-averaged 2-D hydrodynamic model of ecosystem is established under combination of wetland plants, bed mud, and water change. The model is applied to simulate flow and concentration fields of present lake water, and lake waters after breakwater removal and wetland build. It is also used to simulate concentration field of wastewater discharged into Dian Lake which meets the discharge standard. The influences of wetland plants and water expanding on flow field and water quality are analyzed, and the effect of wastewater discharged into Dian Lake which meets the discharge standard on water quality is analyzed, too. The results show that: The influence of water expanding on flow field is local; and the influence of wetland plants on flow field occurs primarily at wetland areas; and the influence of water expanding on water quality is not great because the total phosphorus(TP) and the total nitrogen(TN) reduce to 1.69mg/L and 0.16mg/L from 2.08mg/L and 0.19mg/L respectively; and the influence of ecological wetland on water quality is great, because the TP and the TN reduce to 0.76mg/L and 0.05mg/L respectively, which could make the water quality of Dian Lake reach Ⅲ class of The National Surface Water Standards; and the influence of wastewater discharged into Dian Lake which meets the discharge standard on water quality is big, because the TP and the TN reduce to 0.17mg/L and 0.01mg/L respectively, which could obviously improve the water quality. Therefore, wastewater discharged into Dian Lake which meets the discharge standard and artificial wetland play an important role in the improvement of the ecological environment of Dian Lake.

Nanoparticle Precipitation in a T-Mixer: Coupling Experimental and Numerical Investigations of the Fluid Dynamics With the Solid Formation Processes

2006 ◽  
Author(s):  
Johannes Gradl ◽  
Florian Schwertfirm ◽  
Hans-Christoph Schwarzer ◽  
Hans-Joachim Schmid ◽  
Michael Manhart ◽  
...  
Keyword(s):  
Flow Field ◽  
Fluid Dynamic ◽  
Concentration Field ◽  
Population Balance ◽  
Mixing Process ◽  
Image Velocimetry ◽  
Modeling Material ◽  
Field Information ◽  
Set Up ◽  
3D Information

Mixing and consequently fluid dynamic is a key parameter to tailor the particle size distribution (PSD) in nanoparticle precipitation. Due to fast and intensive mixing a static T-mixer configuration is capable for synthesizing continuously nanoparticles. The flow and concentration field of the applied mixer is investigated experimentally at different flow rates by Particle Image Velocimetry (PIV) and Laser Induced Fluorescence (LIF). Due to the PIV measurements the flow field in the mixer was characterized qualitatively and the mixing process itself is quantified by the subsequent LIF-measurements. A special feature of the LIF set up is to detect structures in the flow field, which are smaller than the Batchelor length. Thereby a detailed insight into the mixing process in a static T-Mixer is given. In this study a CFD-based approach using Direct Numerical Simulation (DNS) in combination with the solid formation kinetics solving population balance equations (PBE) is applied, using barium sulfate as modeling material. A Lagrangian Particle Tracking strategy is used to couple the flow field information with a micro mixing model and with the classical theory of nucleation. We found that the DNS-PBE approach including macro and micro mixing, combined with the population balance is capable of predicting the full PSD in nanoparticle precipitation for different operating parameters. Additionally to the resulting PSD, this approach delivers a 3D-information about all running subprocesses in the mixer, i.e. supersaturation built-up or nucleation, which is visualized for different process variables.

scholarly journals Pollutants Sources and Their Discharging Amount in Taihu Lake Area of Jiangsu Province

2000 ◽  
Vol 12 (2) ◽  
pp. 147-153 ◽  
Author(s):  
LI Ronggang ◽  
◽  
XIA Yuanling ◽  
WU Anzhi ◽  
QIAN Yisheng
Keyword(s):  
Taihu Lake ◽  
Jiangsu Province ◽  
Lake Area

scholarly journals CFD Simulation of Pollutant Emission in a Natural Draft Dry Cooling Tower with Flue Gas Injection: Comparison between LES and RANS

Energies ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3630
Author(s):  
Guangjun Yang ◽  
Xiaoxiao Li ◽  
Li Ding ◽  
Fahua Zhu ◽  
Zhigang Wang ◽  
...  
Keyword(s):  
Flow Field ◽  
Flue Gas ◽  
Cooling Tower ◽  
Cfd Simulation ◽  
Concentration Field ◽  
Pollutant Concentration ◽  
Pollutant Emission ◽  
Navier Stokes ◽  
Dry Cooling Tower ◽  
Reynolds Average

Accurate prediction of pollutant dispersion is vital to the energy industry. This study investigated the Computational Fluid Dynamics (CFD) simulation of pollutant emission in a natural draft dry cooling tower (NDDCT) with flue gas injection. In order to predict the diffusion and distribution characteristics of the pollutant more accurately, Large Eddy Simulation (LES) was applied to predict the flow field and pollutant concentration field and compared with Reynolds Average Navier-Stokes (RANS) and Unsteady Reynolds Average Navier-Stokes (URANS). The relationship between pollutant concentration pulsation and velocity pulsation is emphatically analyzed. The results show that the flow field and concentration field simulated by RANS and URANS are very close, and the maximum value of LES is about 43 times that of RANS and URANS for the prediction of pollutant concentration in the inner shell of cooling tower. Pollutant concentration is closely related to local flow field velocity. RANS and URANS differ greatly from LES in flow field prediction, especially at the outlet and downwind of cooling tower. Compared with URANS, LES can simulate flow field pulsation with a smaller scale and higher frequency.

scholarly journals Estimating Dynamics of Terminal Lakes in the Second Largest Endorheic River Basin of Northwestern China from 2000 to 2017 with Landsat Imagery

2019 ◽  
Vol 11 (10) ◽  
pp. 1164
Author(s):  
Bei Li ◽  
Yi-Chi Zhang ◽  
Ping Wang ◽  
Chao-Yang Du ◽  
Jing-Jie Yu
Keyword(s):  
River Basin ◽  
Water Consumption ◽  
Landsat Imagery ◽  
Water Diversion ◽  
Heihe River ◽  
Arid Environments ◽  
Lake Area ◽  
Landsat Images ◽  
East River ◽  
Terminal Lakes

Quantifying terminal-lake dynamics is crucial for understanding water-ecosystem-economy relationship across endorheic river basins in arid environments. In this study, the spatio-temporal variations in terminal lakes of the lower Heihe River Basin were investigated for the first time since the Ecological Water Diversion Project commenced in 2000. The lake area and corresponding water consumption were determined with 248 Landsat images. Vital recovery of lakes occurred two years after the implementation of the project, and the total lake area increased by 382.6%, from 30.7 to 148.2 km2, during 2002–2017. East Juyan Lake (EJL) was first restored as a project target and subsequently reached a maximum area of 70.1 km2. Water dispersion was initiated in 2003, with the East river prioritized for restoration. Swan Lake in the East river enlarged to 67.7 km2 by 2017, while the other four lakes temporarily existed or maintained an area < 7 km2, such as West Juyan Lake. Water consumed by lakes increased synchronously with lake area. The average water consumption of the six lakes was 1.03 × 108 m3/year, with 63% from EJL. The increasing terminal lakes; however, highlight the seasonal competition for water use between riparian vegetation and lake ecosystems in water-limited areas.

Temporal distribution of granitoid plutonic rocks in the Archean Slave Province, northwest Canadian Shield

1992 ◽  
Vol 29 (10) ◽  
pp. 2186-2199 ◽  
Author(s):  
O. van Breemen ◽  
W. J. Davis ◽  
J. E. King
Keyword(s):  
Continental Margin ◽  
Temporal Distribution ◽  
Lake Area ◽  
Margin Setting ◽  
General Terms ◽  
Slave Province ◽  
Age Variation ◽  
Granitoid Rocks ◽  
Plutonic Rocks ◽  
Granitoid Gneisses

Granitoid rocks in the Slave Province consist of 4.0–2.8 Ga granitoid gneisses that predate the 2.71–2.65 Ga volcanic and turbiditic rocks of the Yellowknife Supergroup and 2.70–2.58 Ga granitoid plutons that intrude the Yellowknife Supergroup. U–Pb zircon ages and Nd and Pb isotopic data indicate that the older granitoids are restricted to the western part of the Slave Province. Granitoid gneisses in the eastern Slave Province, previously suspected to predate the Yellowknife Supergroup, are similar in age to the volcanic rocks.In this paper, the results of a detailed geochronological study of plutonic rocks of the Contwoyto Lake – Nose Lake area of the northcentral Slave Province are reviewed and integrated with the available age data base for plutonic rocks elsewhere in the Slave Province. The data indicate that the timing of the later (<2.7 Ga) plutonism is bimodal, consisting of two distinct magmatic periods separated by approximately 20 Ma of apparent magmatic quiescence. The first period was synvolcanic, dating from 2695 to 2650 Ma. The second period, during which more than 80% of the granitoids presently exposed in the Slave Province were intruded, lasted from 2625 to 2580 Ma, spanning the major Archean deformation events, Syndeformation granitoids, with ages between 2625 and 2595 Ma, are dominantly diorite and tonalité in composition. Late- to post-deformation granitoid rocks, with ages between 2605 and 2580 Ma, range in composition from megacrystic biotite granodiorite to two-mica granite. In general terms, the compositions of the granitoid plutons vary in time from dominantly metaluminous to more strongly peraluminous.Present data show no obvious regional age variation among the younger granitoid rocks across the province. This apparent absence of diachroneity has important implications for models interpreting the magmatism as having evolved in a continental-margin setting, because the extent of contemporaneous plutonism is more than 400 km across strike, considerably broader than in most Mesozoic continental-margin batholiths.

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