scholarly journals Mathematical description of water flow quantity for microhydroelectric station

2020 ◽  
Vol 614 ◽  
pp. 012032
Author(s):  
D Kodirov ◽  
O Tursunov ◽  
S Khushiev ◽  
O Bozarov ◽  
G Tashkhodjaeva ◽  
...  
Keyword(s):  
Water Flow ◽  
Mathematical Description ◽  
Flow Quantity

Development of Electric Rust Preventive Machining Method – Optimization of Water Recycle System

2012 ◽  
Vol 523-524 ◽  
pp. 973-978 ◽  
Author(s):  
Naohiro Nishikawa ◽  
Yoshinori Sato ◽  
Fumika Andou ◽  
Takekazu Sawa ◽  
Yoshihiro Hagihara ◽  
...  
Keyword(s):  
Water Flow ◽  
High Speed ◽  
Surface Active Agent ◽  
Health Hazard ◽  
Active Agent ◽  
Test Liquid ◽  
Water Recycle ◽  
Sludge Particle ◽  
Flow Quantity ◽  
Adjustment Test

In production site, machining fluid (cutting oil, grinding fluid) is used. It contains several chemicals that are oil, surface active agent, and extreme pressure agent, anti rust agent and so on. Waste fluid disposal which is incineration etc. is necessary and arise huge cost and environmental load. In addition, workers health hazard is concerned for several chemicals while machining. In this investigation, new water machining method system (electric rust preventive machining method system) that uses only water as machining fluid for solving of conventional machining fluid problems is developed. In particularly, this paper mentions optimization of used machining water recycle on purification rate and refined water flow quantity in developed water recycle system. Therefore, high speed adjustment test liquid equipment is developed for stable experimental condition for evaluation. Test liquid turbidity is random for sludge particle and simple filter decreases this fluctuation. However, water recycle system is aimed for constant refined output despite fluctuation of input dirty water, and it is achieved. The optimized refined water flow quantity is 13.3 L/min at 1.0 MPa from viewpoint of purification on iron, turbidity, colour, conductivity and flow rate and purification load for reverse osmosis membrane.

A Mathematical Description of Water Flow through Plant Tissues

1996 ◽  
Vol 180 (1) ◽  
pp. 61-70 ◽  
Author(s):  
Paul J. Schulte ◽  
David G. Costa
Keyword(s):  
Water Flow ◽  
Mathematical Description ◽  
Plant Tissues ◽  
Flow Through

Effect of verapamil on cytoplasmic distribution of granules and microfilaments in amphibian urinary bladder

1988 ◽  
Vol 46 ◽  
pp. 324-325
Author(s):  
A.J. Mia ◽  
L.X. Oakford ◽  
T. Yorio
Keyword(s):  
Urinary Bladder ◽  
Water Flow ◽  
Morphological Changes ◽  
Granular Cell ◽  
Cytosolic Calcium ◽  
Calcium Storage ◽  
Amphibian Urinary Bladder ◽  
Vesicular Membrane ◽  
High Concentrations ◽  
Cytoskeletal System

The amphibian urinary bladder has been used as a ‘model’ system for studies of the mechanism of action of antidiuretic hormone (ADH) in stimulating transepithelial water flow. The increase in water permeability is accompanied by morphological changes that include the stimulation of apical microvilli, mobilization of microtubules and microfilaments and vesicular membrane fusion events . It has been shown that alterations in the cytosolic calcium concentrations can inhibit ADH transmembrane water flow and induce alterations in the epithelial cell cytomorphology, including the cytoskeletal system . Recently, the subapical granules of the granular cell in the amphibian urinary bladder have been shown to contain high concentrations of calcium, and it was suggested that these cytoplasmic constituents may act as calcium storage sites for intracellular calcium homeostasis. The present study utilizes the calcium antagonist, verapamil, to examine the effect of calcium deprivation on the cytomorphological features of epithelial cells from amphibian urinary bladder, with particular emphasis on subapical granule and microfilament distribution.

Water Flow Modelling of the Venice Lagoon

1993 ◽  
Author(s):  
Enrico Marchi ◽  
Attilio Adami ◽  
Alfredo Caielli ◽  
Giovanni Cecconi
Keyword(s):  
Water Flow ◽  
Venice Lagoon ◽  
Flow Modelling

Investigation of the influence of the flow structure on the accuracy of flow measurement before a hydrometric structure in an open channel

2020 ◽  
pp. 41-44
Author(s):  
Anatoly Kusher
Keyword(s):  
Velocity Profile ◽  
Flow Velocity ◽  
Water Flow ◽  
Flow Measurement ◽  
Water Discharge ◽  
Critical Depth ◽  
Flow Measurements ◽  
Study Results ◽  
Flow Velocity Profile ◽  
Upstream Flow

The reliability of water flow measurement in irrigational canals depends on the measurement method and design features of the flow-measuring structure and the upstream flow velocity profile. The flow velocity profile is a function of the channel geometry and wall roughness. The article presents the study results of the influence of the upstream flow velocity profile on the discharge measurement accuracy. For this, the physical and numerical modeling of two structures was carried out: a critical depth flume and a hydrometric overfall in a rectangular channel. According to the data of numerical simulation of the critical depth flume with a uniform and parabolic (1/7) velocity profile in the upstream channel, the values of water discharge differ very little from the experimental values in the laboratory model with a similar geometry (δ < 2 %). In contrast to the critical depth flume, a change in the velocity profile only due to an increase in the height of the bottom roughness by 3 mm causes a decrease of the overfall discharge coefficient by 4…5 %. According to the results of the numerical and physical modeling, it was found that an increase of backwater by hydrometric structure reduces the influence of the upstream flow velocity profile and increases the reliability of water flow measurements.

Intensification of Open Gutters Operation

2020 ◽  
pp. 66-70
Keyword(s):  
Water Flow ◽  
Vortex Formation ◽  
Hydraulic Testing ◽  
Polymer Materials ◽  
Bottom Surface ◽  
Artificial Roughness ◽  
Transport Capacity ◽  
Corrugated Surfaces ◽  
Inner Surface ◽  
Dispersed Inclusions

The intensification of the work of open gutter by applying textured shells to their bottom surface, forming an artificial roughness, is considered. It is shown that the presence of corrugated surfaces contributes to vortex formation during water flow and improves the separation and transportation of mineral impurities previously dropped into the bottom of the gutters. The implementation of operations to improve the structure of the gutters is possible during the repair and restoration works with the use of modern polymer materials. The design of a small-sized hydraulic stand, which makes it possible to study the transport capacity of flows containing solid inclusions, is presented. The method of research is hydraulic testing, accompanied by the use of chiaroscuro effect, as well as photo and film equipment. The optimal structure of the inner surface of the gutters and pipes providing vortex formation, which will improve the ability of the flow to carry out and transport foreign dispersed inclusions (sand) of different granulometric compositions, is determined.

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.

Analytical solution for estimating the influence of a pre-existing ground water flow on a geothermal heat production-injection well system

2011 ◽  
Vol 2 (1) ◽  
pp. 13-17
Author(s):  
I. David ◽  
M. Visescu
Keyword(s):  
Ground Water ◽  
Water Flow ◽  
Geothermal Energy ◽  
Flow Direction ◽  
Energy Resource ◽  
Hot Water ◽  
Injection Well ◽  
Production Well ◽  
Ground Water Flow ◽  
The Earth

Abstract Geothermal energy source is the heat from the Earth, which ranges from the shallow ground (the upper 100 m of the Earth) to the hot water and hot rock which is a few thousand meters beneath the Earth's surface. In both cases the so-called open systems for geothermal energy resource exploitation consist of a groundwater production well to supply heat energy and an injection well to return the cooled water, from the heat pump after the thermal energy transfer, in the underground. In the paper an analytical method for a rapid estimation of the ground water flow direction effect on the coupled production well and injection well system will be proposed. The method will be illustrated with solutions and images for representative flow directions respect to the axis of the production/injection well system.

Experimental Investigation of a Two-Phase (Air-Water) Flow in a Pipe with Street Canyon Cavities

2014 ◽  
Vol 8 (6) ◽  
pp. 1149
Author(s):  
Dimitra A. Zoga ◽  
Dimitrios S. Georgakis-Gavrilis ◽  
Dionissios P. Margaris
Keyword(s):  
Experimental Investigation ◽  
Water Flow ◽  
Street Canyon ◽  
Two Phase
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