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.

scholarly journals Transportation of liquid and sand in open trays

2019 ◽  
Vol 97 ◽  
pp. 02003
Author(s):  
Irina Dezhina ◽  
Vladimir Orlov
Keyword(s):  
Quantitative Assessment ◽  
Sand Dunes ◽  
Vortex Formation ◽  
Sand Transport ◽  
Exploratory Research ◽  
Artificial Roughness ◽  
Design Data ◽  
Large Size ◽  
Wide Range ◽  
Inner Surface

Herein there are theoretical dispositions on the conditions of the fluid flow and sand transportation within a wide range of rates. The results of some exploratory research on the sand transport in specially designed laboratory and production benches, including a platform with interchangeable modular polymer elements having an artificial rough surface, have been presented. The ranges of the experiment procedure have been established to create the turbulence zones, where the tray inner surfaces are of various texture in the form of obstacles of different height. The technique has been presented for carrying out experiments on large-size benches with modular pipe elements based on the use of photo and film equipment, as well as a set of devices for determining rates, filling and slopes. The results of hydraulic experiments on modeling the process of vortex formation in the flow in the trays with artificial roughness are presented. The ability of the flow to move sand dunes in the trays with an alternative texture of the inner surface has been studied, and the design data of the quantitative assessment of the transporting ability of the flow depending on various factors has been given.

scholarly journals Flow structure from a horizontal cylinder coincident with a free surface in shallow water flow

2012 ◽  
Vol 16 (1) ◽  
pp. 93-107 ◽  
Author(s):  
Ali Kahraman ◽  
Muammer Özgören ◽  
Beşir Şahin
Keyword(s):  
Free Surface ◽  
Shallow Water ◽  
Water Flow ◽  
Vortex Formation ◽  
Flow Characteristics ◽  
Lower Surface ◽  
Horizontal Cylinder ◽  
Bottom Surface ◽  
Shallow Water Flow ◽  
Cylinder Diameter

Vortex formation from a horizontal cylinder coincident with a free surface of a shallow water flow having a depth of 25.4 [mm] was experimentally investigated using the PIV technique. Instantaneous and time-averaged flow patterns in the wake region of the cylinder were examined for three different cylinder diameter values under the fully developed turbulent boundary layer condition. Reynolds numbers were in the range of 1124? Re? 3374 and Froude numbers were in the range of 0.41 ? Fr ? 0.71 based on the cylinder diameter. It was found that a jet-like flow giving rise to increasing the flow entrainment between the core and wake regions depending on the cylinder diameter was formed between the lower surface of the cylinder and bottom surface of the channel. Vorticity intensity, Reynolds stress correlations and the primary recirculating bubble lengths were grown to higher values with increasing the cylinder diameter. On the other hand, in the case of the lowest level of the jet-like flow emanating from the beneath of the smallest cylinder, the variation of flow characteristics were attenuated significantly in a shorter distance. The variation of the reattachment location of the separated flow to the free-surface is a strong function of the cylinder diameter and the Froude number.

scholarly journals Characteristics of bladeless turbine

2016 ◽  
Vol 61 (No. 2) ◽  
pp. 87-91
Author(s):  
L. Dlabal ◽  
M. Polák
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
Electrical Power ◽  
Water Flow Rate ◽  
Hydraulic Testing ◽  
Point Of View ◽  
Francis Turbine ◽  
Operating Characteristics ◽  
Water Gradient ◽  
Electrical Power Output

The project objective was to perform laboratory tests of the SETUR DVE 120 bladeless turbine and to analyse its measured parameters. Operating characteristics were then determined based on the measured values. The measurement was performed in a closed hydraulic testing circuit in a laboratory of the Department of Mechanical Engineering, Faculty of Engineering, Czech University of Life Sciences Prague. The first part of the article describes the workplace and the method of measurement of the main and the auxiliary parameters. The second part deals with the turbine characteristics. The characteristics describe the relationship between the water flow rate and the usable water gradient and between the water flow rate and the electrical power output of DVE 120, which is important from the user’s point of view. The conclusion features a comparison of the bladeless turbine operating characteristics (dependency of the overall efficiency on the waterpower) and the characteristics of the Francis turbine.

scholarly journals Corrosion Localization Analysis in T-Shape Pipe Junction Based on Multielectrode Current Measurements

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Georgii S. Vasyliev
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
Water Distribution ◽  
Tap Water ◽  
Water Flow Rate ◽  
Galvanic Current ◽  
Steel Electrode ◽  
Steel Pipes ◽  
Inner Surface ◽  
Localization Analysis

The water flow rate and galvanic current distribution in the T-shape junction of steel pipes were investigated using the multielectrode array approach. The inner surface of polypropylene pipes junction was divided into 15 separate sections, and a steel plate was placed in every section to form a single inner surface. The tap water flow rate varied between 0.28 and 0.57 m/s, and the water distribution in the junction was between 5 : 1 and 1 : 5. The galvanic current flowing through each steel electrode was mapped on the 3D model of the T-shape junction. Two differential aeration pairs were found with high anodic current densities.

Transient Critical Heat Fluxes of Subcooled Water Flow Boiling in a Short Vertical Tube Caused by Exponentially Increasing Heat Inputs

2008 ◽  
Vol 130 (5) ◽  
Author(s):  
Koichi Hata ◽  
Nobuaki Noda
Keyword(s):  
Water Flow ◽  
Flow Boiling ◽  
Vertical Tube ◽  
Heat Fluxes ◽  
High Heating Rate ◽  
Subcooled Flow Boiling ◽  
Subcooled Water ◽  
Subcooled Flow ◽  
Inner Surface ◽  
High Heating

The transient critical heat fluxes (CHFs) of the subcooled water flow boiling for the flow velocities (u=4.0–13.3m∕s), the inlet subcoolings (ΔTsub,in=68.08–161.12K), the inlet pressures (Pin=718.31–1314.62kPa), the dissolved oxygen concentrations (O2=2.94ppm to the saturated one), and the exponentially increasing heat inputs (Q0exp(t∕τ), τ=16.82msto15.52s) are systematically measured with an experimental water loop comprised of a pressurizer. The SUS304 tubes of the inner diameters (d=3mm, 6mm, 9mm, and 12mm), heated lengths (L=33.15–132.9mm), L∕d=5.48–11.08, and wall thickness (δ=0.3mm and 0.5mm) with the rough finished inner surface (surface roughness, Ra=3.18μm) are used in this work. The transient CHF data (qcr,sub=6.91–60MW∕m2) are compared with the values calculated by the steady state CHF correlations against inlet and outlet subcoolings. The transient CHF correlations against inlet and outlet subcoolings are derived based on the experimental data. The dominant mechanisms of the subcooled flow boiling CHF for a high heating rate are discussed.

Convective Heat Transfer Investigation of a Confined Air Slot-Jet Impingement Cooling on Corrugated Surfaces With Different Wave Shapes

2018 ◽  
Vol 141 (2) ◽  
Author(s):  
Recep Ekiciler ◽  
Muhammet Samet Ali Çetinkaya ◽  
Kamil Arslan
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Nusselt Number ◽  
Flow Characteristics ◽  
Jet Impingement ◽  
Working Fluid ◽  
Bottom Surface ◽  
Air Jet ◽  
Corrugated Surfaces ◽  
Energy Equations

In this study, air jet impingement on flat, triangular-corrugated, and sinusoidal-corrugated surfaces was numerically investigated. Bottom surface was subjected to constant surface temperature. Air was the working fluid. The air exited from a rectangular shaped slot and impinged on the bottom surface. The Reynolds number was changed between 125 and 500. The continuity, momentum, and energy equations were solved using the finite volume method. The effect of the shape of bottom surface on heat and flow characteristics was investigated in detail. Average and local Nusselt number were calculated for each case. It was found out that Nusselt number increases by increasing the Reynolds number. The optimum conditions were established to get much more enhancement in terms of performance evaluation criterion (PEC). It was revealed that the shape of the cooling surface (bottom wall) influences the heat transfer substantially.

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