The regularity of wind-induced sediment resuspension in Meiliang Bay of Lake Taihu

2014 ◽  
Vol 70 (1) ◽  
pp. 167-174 ◽  
Author(s):  
Jianjian Wang ◽  
Yong Pang ◽  
Yiping Li ◽  
Yawen Huang ◽  
Junjie Jia ◽  
...  
Keyword(s):  
Wind Speed ◽  
Release Rate ◽  
Lake Taihu ◽  
Sediment Resuspension ◽  
Quantitative Relationship ◽  
Phosphorus Release ◽  
Hydrodynamic Conditions ◽  
Wind Speeds ◽  
Resuspension Rate ◽  
Meiliang Bay

Contaminants released by wind-induced sediment resuspension could influence the water quality in shallow lakes. This study aims to reveal the quantitative relationship between wind speed (v) and sediment resuspension rate (r) in Meiliang Bay of Lake Taihu. The study was conducted in three steps. First, the in situ wind speed and current velocity were measured over a period of 2 days in Meiliang Bay to establish the relationship between wind and hydrodynamic conditions; second, an indoor experiment was conducted in a cylindrical simulator with sediment from the study area to determine sediment resuspension rates under different hydrodynamic conditions; and third, linkages between sediment resuspension and wind were determined. The average sediment resuspension rate was highly correlated with the wind speed (R2 = 0.99), and was expressed by r = 20.72v2.034 at wind speeds in the range of 0–14 m/s. The critical wind speed for sediment resuspension is about 7 m/s. Under these conditions, the average resuspension rate could reach 1,000 g/(m2d), with a total phosphorus release rate of 1.1 g/(m2d) and a total nitrogen release rate of 18.1 g/(m2d).

scholarly journals Dynamic simulation of sediment resuspension and its effect on water quality in Lake Taihu, China

2017 ◽  
Vol 17 (5) ◽  
pp. 1335-1346 ◽  
Author(s):  
Jianjian Wang ◽  
Qiaohua Zhao ◽  
Yong Pang ◽  
Yiping Li ◽  
Zhiguo Yu ◽  
...  
Keyword(s):  
Water Quality ◽  
Wind Speed ◽  
Spatial Variation ◽  
Central Region ◽  
Release Rate ◽  
Pollution Control ◽  
Lake Taihu ◽  
Sediment Resuspension ◽  
Water Safety ◽  
Sediment Release

Quantitative studies on sediment release fluxes and their impact on water quality are important for water pollution control, ecological restoration, water safety, and human health. In this study, we conducted high-frequency, synchronous field observations of meteorology, hydrology, and water quality to determine the relationship between sediment release rate and wind speed in the central region of Lake Taihu. We combined these results with our previous findings from other regions to establish the temporal–spatial variation in sediment release patterns for this lake. We then calculated the annual total nitrogen (TN) and total phosphorus (TP) release fluxes. We constructed an environmental fluid dynamics code (EFDC) model; we then loaded the temporal–spatial variation parameters and simulated the effects on different TN and TP concentrations. Overall, the following results were observed: (1) the critical wind speed at which sediment was first suspended in the central region of the lake was 4 m/s, and the fitted curve of the sediment release rate and wind speed was r = 144.7x−100 (R2 = 0.851); and (2) the annual TN and TP release fluxes of Lake Taihu were approximately 3,086 and 740 tons, respectively. This research would provide a basis for decision-making regarding pollution control in this region.

Phosphorus release from cyanobacterial blooms in Meiliang Bay of Lake Taihu, China

2011 ◽  
Vol 37 (6) ◽  
pp. 842-849 ◽  
Author(s):  
Xiaoming Chuai ◽  
Wei Ding ◽  
Xiaofeng Chen ◽  
Xiaolin Wang ◽  
Aijun Miao ◽  
...  
Keyword(s):  
Lake Taihu ◽  
Phosphorus Release ◽  
Cyanobacterial Blooms ◽  
Meiliang Bay

The Effects of Aquatic Plant Vallisneria Natans on the Distribution of Metals under Different Hydrodynamic Conditions

2015 ◽  
Vol 737 ◽  
pp. 362-366
Author(s):  
Yang Lei ◽  
Pei Fang Wang ◽  
Wei Min Zhang
Keyword(s):  
Wind Speed ◽  
Pore Water ◽  
Aquatic Plant ◽  
Sediment Resuspension ◽  
Sediment Accumulation ◽  
Accumulation Factor ◽  
Overlying Water ◽  
Wind Speeds ◽  
Vallisneria Natans ◽  
Hydrodynamic Disturbance

Heavy metals will be released to the water column during the sediment resuspension, causing the secondary pollution to the water ecosystem. In this study, the sediment collected from Zhushan Bay was placed in three similar pneumatic annular flumes where the wind speeds supplied by blast blowers were 3.21m/s, 5.95m/s and 8.78m/s respectively. The physicochemical parameters of the water and concentrations of metals in the water, plants and sediment were measured during the relevant experiments. The result showed that the concentrations of metals in the overlying water increased while it decreased in the pore water with the hydrodynamic disturbance. The aquatic plant Vallisneria natans bioaccumulated metals in the sediment and water, and the plant roots showed a higher ability in assimilating metals than the leaves. Meanwhile a positive correlation was found between wind speed and release amount of metals in pore water. In addition, the relationship between the wind speed and the biota-sediment accumulation factor (BSAF) was different due to the different features of metals.

scholarly journals Characteristic of phosphorus release with the control of pH of sediments from Meiliang Bay, Lake Taihu

2009 ◽  
Vol 21 (5) ◽  
pp. 663-668 ◽  
Author(s):  
YUAN Hezhong ◽  
◽  
SHEN Ji ◽  
LIU Enfeng ◽  
MENG Xianghua ◽  
...  
Keyword(s):  
Lake Taihu ◽  
Phosphorus Release ◽  
Meiliang Bay

SHAPING OF AN AUTONOMOUS POWER SYSTEM FOR GUARANTEED POWER SUPPLY WITH THE PREDOMINANCE WIND ENERGY

2018 ◽  
pp. 28-50
Author(s):  
S. G. Ignatiev ◽  
S. V. Kiseleva
Keyword(s):  
Energy Storage ◽  
Wind Speed ◽  
Wind Energy ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Energy Demand ◽  
Diesel Generator ◽  
Average Wind Speed ◽  
Wind Speeds ◽  
Average Wind

Optimization of the autonomous wind-diesel plants composition and of their power for guaranteed energy supply, despite the long history of research, the diversity of approaches and methods, is an urgent problem. In this paper, a detailed analysis of the wind energy characteristics is proposed to shape an autonomous power system for a guaranteed power supply with predominance wind energy. The analysis was carried out on the basis of wind speed measurements in the south of the European part of Russia during 8 months at different heights with a discreteness of 10 minutes. As a result, we have obtained a sequence of average daily wind speeds and the sequences constructed by arbitrary variations in the distribution of average daily wind speeds in this interval. These sequences have been used to calculate energy balances in systems (wind turbines + diesel generator + consumer with constant and limited daily energy demand) and (wind turbines + diesel generator + consumer with constant and limited daily energy demand + energy storage). In order to maximize the use of wind energy, the wind turbine integrally for the period in question is assumed to produce the required amount of energy. For the generality of consideration, we have introduced the relative values of the required energy, relative energy produced by the wind turbine and the diesel generator and relative storage capacity by normalizing them to the swept area of the wind wheel. The paper shows the effect of the average wind speed over the period on the energy characteristics of the system (wind turbine + diesel generator + consumer). It was found that the wind turbine energy produced, wind turbine energy used by the consumer, fuel consumption, and fuel economy depend (close to cubic dependence) upon the specified average wind speed. It was found that, for the same system with a limited amount of required energy and high average wind speed over the period, the wind turbines with lower generator power and smaller wind wheel radius use wind energy more efficiently than the wind turbines with higher generator power and larger wind wheel radius at less average wind speed. For the system (wind turbine + diesel generator + energy storage + consumer) with increasing average speed for a given amount of energy required, which in general is covered by the energy production of wind turbines for the period, the maximum size capacity of the storage device decreases. With decreasing the energy storage capacity, the influence of the random nature of the change in wind speed decreases, and at some values of the relative capacity, it can be neglected.

scholarly journals Analysis of Performance of the Wind-Driven Pulverizing Aerator Based on Average Wind Speeds in the Conditions of Góreckie Lake

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2796
Author(s):  
Andrzej Osuch ◽  
Ewa Osuch ◽  
Stanisław Podsiadłowski ◽  
Piotr Rybacki
Keyword(s):  
Mathematical Model ◽  
Wind Speed ◽  
Water Pump ◽  
Average Wind Speed ◽  
Flow Rates ◽  
Wind Speeds ◽  
Average Wind ◽  
Flow Through ◽  
Analysis Of Performance ◽  
Research Period

In the introduction to this paper, the characteristics of Góreckie lake and the construction and operation of the wind-driven pulverizing aerator are presented. The purpose of this manuscript is to determine the efficiency of the pulverizing aerator unit in the windy conditions of Góreckie Lake. The efficiency of the pulverization aerator depends on the wind conditions at the lake. It was necessary to conduct thorough research to determine the efficiency of water flow through the pulverization segment (water pump). It was necessary to determine the rotational speed of the paddle wheel, which depended on the average wind speed. Throughout the research period, measurements of hourly average wind speed were carried out. It was possible to determine the efficiency of the machine by developing a dedicated mathematical model. The latest method was used in the research, consisting of determining the theoretical volumetric flow rates of water in the pulverizing aerator unit, based on average hourly wind speeds. Pulverization efficiency under the conditions of Góreckie Lake was determined based on 6600 average wind speeds for spring, summer and autumn, 2018. Based on the model, the theoretical efficiency of the machine was calculated, which, under the conditions of Góreckie Lake, amounted to 75,000 m3 per year.

scholarly journals Optimization of a Small Wind Power Plant for Annual Wind Speed Distribution

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1587
Author(s):  
Krzysztof Wrobel ◽  
Krzysztof Tomczewski ◽  
Artur Sliwinski ◽  
Andrzej Tomczewski
Keyword(s):  
Wind Speed ◽  
Power Plant ◽  
Wind Power ◽  
Power Plants ◽  
Control Method ◽  
Wind Power Plant ◽  
Switched Reluctance ◽  
Wind Speeds ◽  
Wind Speed Distribution ◽  
And Control

This article presents a method to adjust the elements of a small wind power plant to the wind speed characterized by the highest annual level of energy. Tests were carried out on the basis of annual wind distributions at three locations. The standard range of wind speeds was reduced to that resulting from the annual wind speed distributions in these locations. The construction of the generators and the method of their excitation were adapted to the characteristics of the turbines. The results obtained for the designed power plants were compared with those obtained for a power plant with a commercial turbine adapted to a wind speed of 10 mps. The generator structure and control method were optimized using a genetic algorithm in the MATLAB program (Mathworks, Natick, MA, USA); magnetostatic calculations were carried out using the FEMM program; the simulations were conducted using a proprietary simulation program. The simulation results were verified by measurement for a switched reluctance machine of the same voltage, power, and design. Finally, the yields of the designed generators in various locations were determined.

scholarly journals A Novel Sea Surface Roughness Parameterization Based on Wave State and Sea Foam

2021 ◽  
Vol 9 (3) ◽  
pp. 246
Author(s):  
Difu Sun ◽  
Junqiang Song ◽  
Xiaoyong Li ◽  
Kaijun Ren ◽  
Hongze Leng
Keyword(s):  
Surface Roughness ◽  
Wind Speed ◽  
Drag Coefficient ◽  
Sea Surface ◽  
High Wind Speed ◽  
Wave State ◽  
Wind Speeds ◽  
Sea Surface Roughness ◽  
Extreme Wind ◽  
The Impact

A wave state related sea surface roughness parameterization scheme that takes into account the impact of sea foam is proposed in this study. Using eight observational datasets, the performances of two most widely used wave state related parameterizations are examined under various wave conditions. Based on the different performances of two wave state related parameterizations under different wave state, and by introducing the effect of sea foam, a new sea surface roughness parameterization suitable for low to extreme wind conditions is proposed. The behaviors of drag coefficient predicted by the proposed parameterization match the field and laboratory measurements well. It is shown that the drag coefficient increases with the increasing wind speed under low and moderate wind speed conditions, and then decreases with increasing wind speed, due to the effect of sea foam under high wind speed conditions. The maximum values of the drag coefficient are reached when the 10 m wind speeds are in the range of 30–35 m/s.

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