scholarly journals Change of wind flow speed in the protective belt-road system in the conditions of North Kazakhstan

2020 ◽  
Author(s):  
I.A. Zdornov ◽  
Z.Ya. Nagimov ◽  
A.V. Kapralov
Keyword(s):  
Flow Speed ◽  
Wind Flow ◽  
Protective Belt ◽  
Road System

scholarly journals Estimating air pollution levels by numerical simulation depending on wind flow speed and dust source area

2020 ◽  
pp. 80-89
Author(s):  
Amosov Pavel ◽  
◽  
Baklanov Alexander ◽  
Makarov Dmitriy ◽  
Masloboev Vladimir ◽  
...  
Keyword(s):  
Atmospheric Pollution ◽  
Source Area ◽  
Flow Speed ◽  
Wind Flow ◽  
Tailing Dump ◽  
Dust Source ◽  
Pollution Levels ◽  
Aerodynamic Properties ◽  
Dust Sources ◽  
The Town

Research aim is to estimate atmospheric pollution levels in the town of Apatity, by numerical simulation, depending on the discrete arrangement of dust sources at the tailing dump closest to the town and the speed of wind flow. Methodology. For computer 3D modeling, the COMSOL software was used. To calculate the aerodynamic properties the approach of incompressible fluid and standard (k–ε)-model of turbulence were used. The spread of dust pollution has been modeled by numerically solving the convective-diffusion equation of impurity transfer taking into account the deposition rate. Numerical experiments were performed for wind flow speeds between 5 and 23 m/s and a discrete representation of the dust source area between 2 and 10 ha. Results. The spatial distributions of the model's aerodynamic properties and the interval (and total) distributions of dust pollution were obtained. The Starye Apatity area is most exposed to atmospheric pollution. Atmospheric pollution levels were analyzed and generalized to functional dependencies, depending on the values of the model's variable parameters. It is shown that the calculated dependencies between the maximum dust concentration and the dust source area can be described by linear functions, which allows predicting the critical dust source area, at which the level of air pollution reaches the threshold limit value. It is demonstrated that the dependence of the maximum dust concentration on wind flow speed at fixed dust source area values can be approximated by a power-law function. Summary. A generalized analytical formula has been derived that allows predicting maximum dust concentrations in the town of Apatity depending on the discrete locations of dust sources at the tailing dump and the speed of wind flow.

Study on the Modes of Operation of a Multi-Machine Installations with Mechanical Reduction

2019 ◽  
pp. 12-22
Author(s):  
A. M. Oleynikov ◽  
L. N. Kanov
Keyword(s):  
Mathematical Description ◽  
Reactive Power ◽  
Maximum Efficiency ◽  
Wind Flow ◽  
System Of Equations ◽  
Mechanical Equilibrium ◽  
Synchronous Generators ◽  
Electromagnetic Excitation ◽  
Number Of Generators ◽  
Wide Range

The paper gives the description of the original wind electrical installation with mechanical reduction in which the output of vertical axis wind turbine with rather low rotation speed over multiplicator is distributed to a certain number of generators. The number of acting generators is determined by the output of actual operating wind stream at each moment. According to this constructive scheme, it is possible to provide effective and with maximum efficiency installation work in a wide range of wind speeds and under any schedule issued to the consumer of electricity. As there are no any experience in using such complexes, mathematical description of its main elements is given, namely windwheels, generators with electromagnetic excitation of magnetic electrical type, then their interaction with windwheel, and also the results of mathematical modeling of work system regimes under using the offered system of equations. The basis for the mathematical description of the main elements of the installation – synchronous generators – are the system of equations of electrical and mechanical equilibrium in relative units in rotating coordinates without considering saturation of the magnetic circuit. The equation of mechanical equilibrium systems includes torque and brake windwheel electromagnetic moments of generators with taking into account the reduction coefficients and friction. In addition, we specify the alternator rotor dynamics resulting from continuous torque of windwheel fluctuations under the influence of unsteady wind flow and wind speed serving as the original variable is modeled by a set of sinusoids. Model simplification is achieved by equivalization of similar generators and by disregarding these transitions with a small time constant. Calculation the installation with synchronous generators of two types of small and medium capacity taking into account the operational factors allowed us to demonstrate the logic of interactions in the main elements of the reported complex in the process of converting wind flow into the generated active and reactive power. We have shown the possibility of stable system work under changeable wind stream condition by regulating of the plant blade angle and with simultaneous varying of generator number of different types. All these are in great interest for project organizations and power producers.

Increase Power Efficientand Reliability of Electrosupply of Consumers of Low Power

GIS Business ◽  
2019 ◽  
Vol 14 (4) ◽  
pp. 42-52
Author(s):  
Sadullayev Nasillo Nematovich ◽  
Safarov Alisher Bekmurodovich ◽  
Nematov Shuhrat Nasilloyevich ◽  
Mamedov Rasul Akif- Ogli
Keyword(s):  
Wind Speed ◽  
Probability Distribution ◽  
Low Power ◽  
Electric Power ◽  
Energy Sources ◽  
Wind Flow ◽  
Wind Rose ◽  
Energy Potential ◽  
Wind Power Installation ◽  
Wind Energy Potential

This article assesses the wind speed data and wind energy potential in the Bukhara region of Uzbekistan. In article it is stated a principle construction "hybrid" a source of the electric power consisting from wind power installation with mechanical store of energy, the solar panel with аккумулятор in common working with an electric network. The speed and direction of the wind measured at a height of 10 m were analyzed by the Weibull probability distribution functionTo determine the direction of wind flow (wind rose), a graph in Matlab environment was constructed. The method of an estimation energy of efficiency of the objects eating from several energy sources is offered. It is proved efficiency of application of such source of the electric power low power consumers

Flow speed and calving rate of Kongsbreen glacier, Svalbard, using SPOT images

1994 ◽  
Vol 13 (1) ◽  
pp. 59-65 ◽  
Author(s):  
Bernard Lefauconnier ◽  
Jon Ove Hagen ◽  
Jean Paul Rudant
Keyword(s):  
Flow Speed ◽  
Calving Rate

The Turnpike Road System in England, 1663-1840

1973 ◽  
Vol 14 (2) ◽  
pp. 307
Author(s):  
John B. Rae ◽  
William Albert
Keyword(s):  
Road System

Interactions between a planktivorous fish and planktonic microcrustaceans mediated by the biomass of aquatic macrophytes

2021 ◽  
Author(s):  
Bárbara Angélio Quirino ◽  
Franco Teixeira de Mello ◽  
Sabrina Deosti ◽  
Claudia Costa Bonecker ◽  
Ana Lúcia Paz Cardozo ◽  
...  
Keyword(s):  
Aquatic Macrophyte ◽  
Plant Biomass ◽  
Flow Speed ◽  
Trophic Niche ◽  
Planktivorous Fish ◽  
Low Flow ◽  
High Biomass ◽  
Predator Prey ◽  
Cladoceran Species ◽  
Macrophyte Biomass

Abstract Habitat complexity is recognized to mediate predator–prey relationships by offering refuge or not. We investigated the availability of planktonic microcrustaceans and the diet of a planktivorous fish (Hyphessobrycon eques) at different levels (low, intermediate and high) of aquatic macrophyte biomass. Sampling was carried out in a river with low flow speed, located in a Neotropical floodplain. We collected fish and microcrustaceans in macrophyte stands with variations in biomass. There were no differences in microcrustacean density in the water among the levels of macrophyte biomass, but microcrustacean richness and diet composition of H. eques differed. Microcrustacean richness and trophic niche breadth of the planktivorous fish were higher in high biomass stands. There was high consumption of a small cladoceran species in low macrophyte biomass, which was replaced by larger species, such as copepods, in intermediate and high biomass. Thus, the selection of some species was different among the biomass levels. These results suggest that plant biomass plays an important role in the interaction between fish and microcrustaceans, and prey characteristics such as size, escape ability and energy value make them more or less subject to predation by fish according to habitat structuring.

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