scholarly journals Explanation of tuberculation scales formation in steel and iron pipes using the theory of wave motion of a liquid

2018 ◽  
Vol 178 ◽  
pp. 04002
Author(s):  
Alexey Andrianov ◽  
Evgeny Orlov
Keyword(s):  
Flow Velocity ◽  
Water Flow ◽  
Electrochemical Corrosion ◽  
Water Supply Systems ◽  
Water Flow Velocity ◽  
Corrosion Deposits ◽  
The Difference ◽  
Corrosion Of Steel ◽  
Supply Systems ◽  
Turbulent Water

Electrochemical corrosion of steel and iron pipes in water supply systems is a common problem that causes financial losses to operating companies and deteriorates water quality. A comprehensive study of corrosion deposits formation mechanism is necessary for a better understanding of the processes occurring in pipelines and for scientific justification of monitoring and predicting techniques. The influence of various factors (in particular the water flow velocity) on the formation, growth, and spatial distribution of tuberculation scales on the inner surface of pipes is considered. To study the effect of flow velocity, simple serial tests were carried out on segments of a steel non-galvanized pipe in static and dynamic conditions. The difference in the formation of anode and cathode sections in two dynamic modes is recognized. The first stage of tubercle formation is observed. It was assumed that in pipes with turbulent water flow near metal surface, waves forming tubercles are appeared, and the distribution of the tubercles is depend on water flow velocity.

scholarly journals Real Values of Local Resistance Coefficients during Water Flow through Welded Polypropylene T-Junctions

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 895
Author(s):  
Marek Kalenik ◽  
Marek Chalecki ◽  
Piotr Wichowski
Keyword(s):  
Water Flow ◽  
Resistance Coefficient ◽  
Water Supply Systems ◽  
Internal Diameter ◽  
Local Resistance ◽  
Water Flow Velocity ◽  
Local Resistance Coefficient ◽  
Flow Through ◽  
Supply Systems ◽  
Resistance Coefficients

The paper presents results of investigation of the local resistance coefficient ζ in welded polypropylene T-junctions with the internal diameter 13.2 mm. The investigations were performed on an independently constructed test rig. The scope of investigations encompassed the T-junctions, which were (1) properly warmed up and properly pressed, (2) poorly warmed up and poorly pressed, or (3) excessively warmed up and excessively pressed. The local resistance coefficients ζ determined by measurements according to the standard PN-EN 1267:2012(Designation of the Polish Standard) were compared to those determined with use of the nomograms recommended for designing water supply systems and installations. Real values of the coefficients ζ, obtained in measurements were significantly higher than those read from the nomograms. The local resistance coefficients ζ in welded polypropylene T-junctions depend on water flow velocity and the manufacturing precision of a T-junction joint.

The effects of changing water flow velocity on the formation of biofilms and water quality in pilot distribution system consisting of copper or polyethylene pipes

2006 ◽  
Vol 40 (11) ◽  
pp. 2151-2160 ◽  
Author(s):  
Markku J. Lehtola ◽  
Michaela Laxander ◽  
Ilkka T. Miettinen ◽  
Arja Hirvonen ◽  
Terttu Vartiainen ◽  
...  
Keyword(s):  
Water Quality ◽  
Flow Velocity ◽  
Water Flow ◽  
Distribution System ◽  
Water Flow Velocity ◽  
Polyethylene Pipes

Effect of slope gradient on the subsurface water flow velocity of sand layer profile

2020 ◽  
Vol 17 (3) ◽  
pp. 641-652 ◽  
Author(s):  
Zhen Han ◽  
Xiao-yan Chen ◽  
Yu-han Huang ◽  
Bang-lin Luo ◽  
Hang Xing ◽  
...  
Keyword(s):  
Flow Velocity ◽  
Water Flow ◽  
Subsurface Water ◽  
Sand Layer ◽  
Slope Gradient ◽  
Water Flow Velocity

scholarly journals Water load pattern in a production hall

2018 ◽  
Vol 45 ◽  
pp. 00015 ◽  
Author(s):  
Edyta Dudkiewicz ◽  
Alina Żabnieńska-Góra
Keyword(s):  
Flow Velocity ◽  
Water Flow ◽  
Hot Water ◽  
Domestic Water ◽  
Water Flow Velocity ◽  
Water Load ◽  
Actual Volume ◽  
Load Pattern ◽  
And Gender ◽  
Selection Of

The actual volume of water consumption in the various industrial halls is very diverse. Many factors have an impact on that value, depending on the demand for: domestic, fire-fighting, technologically specific target and other purposes. The demand for domestic water in the production hall is primarily due to the use of showers, wash basins and flush toilets. Workplaces should be appropriately equipped with hygienic and sanitary facilities, depending on its degree of soiling, type of work and gender. The water flow is relevant for dimensioning the water supply system including the diameter selection of the water pipes. Criterion for selection of the diameter is the flow velocity of the water which varies depending on the manufacturer’s guidelines, the material used and the law. The article analyses the dynamics of load pattern of hot water in industrial halls. The methods of flow calculation in production halls based on an analysis of patterns available in literature and the water flow velocity criteria is discussed. The results of the research of the dynamics of water load pattern in a production hall located in Wroclaw is presented and discussed.

scholarly journals Application of a Volterra quadratic polynomial to modeling elements of heat engineering devices

2019 ◽  
Vol 114 ◽  
pp. 01007 ◽  
Author(s):  
Ekaterina Antipina ◽  
Vadim Spiryaev ◽  
Emir Tairov
Keyword(s):  
Power Series ◽  
Flow Velocity ◽  
Power Unit ◽  
Water Flow ◽  
Cooling Water ◽  
Steam Flow ◽  
Dynamic Processes ◽  
Water Flow Velocity ◽  
Temperature Changes ◽  
Extreme Problem

This paper considers integral models built to describe dynamic processes in a 135 MW power unit condenser. For this purpose, we use a quadratic segment of the Volterra integral power series. The first set of models was built with a perturbation of the cooling water flow, and the second one with a perturbation of the steam flow. For all sets of models, changes in pressure and temperature in the condenser, as well as temperature changes in LHP-1, were considered as a response to perturbation. For models built with perturbation of the cooling water flow velocity, we considered an extreme problem of finding optimal amplitudes of the input perturbations. The results of calculations proved to be sufficiently accurate.

Surface Tension Analysis of Cost-Effective Paraffin Wax and Water Flow Simulation for Microfluidic Device

2013 ◽  
Vol 832 ◽  
pp. 773-777
Author(s):  
Nurulazirah Md Salih ◽  
U. Hashim ◽  
Nayan Nafarizal ◽  
Chin Fhong Soon ◽  
Mohd Zainizan Sahdan
Keyword(s):  
Surface Tension ◽  
Contact Angle ◽  
Flow Velocity ◽  
Water Flow ◽  
Microfluidic Device ◽  
Flow Simulation ◽  
Channel Length ◽  
Paraffin Wax ◽  
Inlet Channel ◽  
Water Flow Velocity

In microfluidic devices, the most important aspect has to be considered for the manufacturing process is the material suitability and geometric design. Among the materials studied, paraffin wax has never been tested and it is proposed as the new approach in this paper for patterning the microchannels. Furthermore, contact angle analysis of the paraffin wax was also studied. Based on the contact angle measurements; the hydrophobicity and surface tension of paraffin wax were analyzed. From the finding, it shows that paraffin wax has a low surface tension and high hydrophobicity. Then, several microchannels design was simulated using COMSOL multiphysics 4.2 software in order to find the optimized geometry. It involves a study of different shape, diameter, length, and angle of microchannels design, and its influence on the water flow velocity. From the simulation results, an optimize microchannels design was obtained consists of 1000 μm channels diameter, 1000 μm inlet channel length, 1.0 cm outlet channels length, and 110o inlet channel angle with water flow velocity of 2.3cm/s. Further study could be done to improve the finding of properties and geometric suitability for microfluidic device.

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