Elimination of flow rate restriction for system of storm water sewage with the help of drag-reducing polymers

The flow-rate restriction for storm sewage network is substantiated. Possible causes of flooding of territories by storm water in the case of emergency and methods of storm waters management are considered. The article is devoted to an increase in throughput of storm sewage networks with the help of in-line storm water detention tank installed at the beginning of storm sewage network and dragreducing polymers (DRP). It is proposed to introduce DRPs in the form of solution directly into the sewage network through a storm-water inlet or through a sewer manhole. The introduction is conducted from a tank (cistern) in which there is a device for preparing an aqueous solution from the raw materials of DRP. For a square (in horizontal plane) catchment, in the case of point-type water drainage, the numerical simulation of the work of a system of storm water sewage with the help of DRP has been carried out.

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Controlled outflow of storm water without flooding

MATEC Web of Conferences ◽

10.1051/matecconf/201816802001 ◽

2018 ◽

Vol 168 ◽

pp. 02001

Author(s):

Karel Adámek ◽

Jan Kolář ◽

Pavel Peukert

Keyword(s):

Numerical Simulation ◽

Water Level ◽

Flow Rate ◽

Storm Water ◽

Resistance Characteristic ◽

The Given

There are many types of devices used for various purposes, called as vortex valves. The aim of this paper is the design of vortex valves, determined for controlled higher outflows from retention tanks. The paper follows the previous study of smaller sizes of vortex valves. The method of flow numerical simulation allows us to identify the reason of the two-branch operational (resistance) characteristic of the solved valves and the suitable sizes of the main valve dimensions for the given flow rate and water level.

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Performance Comparison of Geodrain Drainage and Gravel Drainage Layers Embedded in a Horizontal Plane

Materials ◽

10.3390/ma14216321 ◽

2021 ◽

Vol 14 (21) ◽

pp. 6321

Author(s):

Mariusz Cholewa ◽

Karol Plesiński

Keyword(s):

Model Test ◽

Flow Rate ◽

Horizontal Plane ◽

Volumetric Flow Rate ◽

Performance Comparison ◽

Test Results ◽

Water Drainage ◽

Gravel Layer ◽

Maximum Value ◽

Drainage Layers

Drainage materials are widely used, among other uses, in the construction of landfills. Regulations require a drainage layer in the base and a covering for the landfill. The implementation of a gravel drain requires a lot of material and financial outlays. New geocomposite materials are an alternative, and facilitate construction. The aim of the research was to compare the drainage properties of the Pozidrain 7S250D/NW8 geocomposite and gravel drainage. The model test was performed on a specially prepared test stand. The research was carried out for model #1, in which the gravel drainage was built. Model #2 had a drainage geocomposite built into it. The test results show the values of the volumetric flow rate for geodrains, with a maximum value of 40 dm3·min−1. For the gravel layer, values of up to 140 dm3·min−1 were recorded. Another parameter recorded during the damming of water by the embankment was the speed of water suction by the geosynthetic and gravel drainage; the values were 0.067 and 0.024 m3·s−1, respectively. The efficiency of water drainage through the geocomposite was sufficient. It is possible to use the slopes of the landfill for drainage, which will reduce material and financial outlays.

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Numerical Simulation of Laminar Confined Radial Flow Between Parallel Circular Discs

Journal of Fluids Engineering ◽

10.1115/1.4005737 ◽

2012 ◽

Vol 134 (1) ◽

Cited By ~ 6

Author(s):

Nirmalendu Biswas ◽

Nirmal Kumar Manna ◽

Achintya Mukhopadhyay ◽

Swarnendu Sen

Keyword(s):

Numerical Simulation ◽

Flow Rate ◽

Horizontal Plane ◽

Radial Flow ◽

Separation Bubble ◽

Computational Domain ◽

Circular Nozzle ◽

Simpler Algorithm ◽

Volume Method ◽

Steady Laminar

In this work, a fluid jet is issued axially from a short, circular nozzle and then fed radially outward through the clearance of two parallel circular discs. The disc assembly was considered fully submerged within a fluid in a horizontal plane. Axisymmetric computational domain is chosen for the analysis considering steady, laminar flow. The numerical simulation is carried out by an in-house CFD code developed following the finite volume method and SIMPLER algorithm. The effects of flow rate and channel dimensions are analyzed to understand the characteristics of submerged radial flow. It is found that the flow field consists of several features like toroidal recirculation, annular separation bubble and flow reattachment, which are strongly influenced by the clearance between the two parallel discs and the flow rate.

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Utilization of Waste of Enzymes Biomass as Biosorbent for the Removal of Dyes from Aqueous Solution in Batch and Fluidized Bed Column

Revista de Chimie ◽

10.37358/rc.20.1.7804 ◽

2020 ◽

Vol 71 (1) ◽

pp. 1-12

Author(s):

Salman H. Abbas ◽

Younis M. Younis ◽

Mohammed K. Hussain ◽

Firas Hashim Kamar ◽

Gheorghe Nechifor ◽

...

Keyword(s):

Experimental Data ◽

Aqueous Solution ◽

Particle Size ◽

Adsorption Capacity ◽

Fluidized Bed ◽

Flow Rate ◽

Fungal Biomass ◽

Solution Flow Rate ◽

Maximum Adsorption Capacity ◽

Solution Flow

The biosorption performance of both batch and liquid-solid fluidized bed operations of dead fungal biomass type (Agaricusbisporus ) for removal of methylene blue from aqueous solution was investigated. In batch system, the adsorption capacity and removal efficiency of dead fungal biomass were evaluated. In fluidized bed system, the experiments were conducted to study the effects of important parameters such as particle size (701-1400�m), initial dye concentration(10-100 mg/L), bed depth (5-15 cm) and solution flow rate (5-20 ml/min) on breakthrough curves. In batch method, the experimental data was modeled using several models (Langmuir,Freundlich, Temkin and Dubinin-Radushkviechmodels) to study equilibrium isotherms, the experimental data followed Langmuir model and the results showed that the maximum adsorption capacity obtained was (28.90, 24.15, 21.23 mg/g) at mean particle size (0.786, 0.935, 1.280 mm) respectively. In Fluidized-bed method, the results show that the total ion uptake and the overall capacity will be decreased with increasing flow rate and increased with increasing initial concentrations, bed depth and decreasing particle size.

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Impacts of urban storm-water drainage channels on a northern Australian mangrove forest

Trees ◽

10.1007/s00468-001-0143-5 ◽

2001 ◽

Vol 16 (2-3) ◽

pp. 195-203 ◽

Cited By ~ 1

Author(s):

Anja Moritz-Zimmermann ◽

Keith A. McGuinness ◽

Manfred Küppers

Keyword(s):

Mangrove Forest ◽

Storm Water ◽

Water Drainage ◽

Drainage Channels ◽

Urban Storm

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Investigation on influences of loose gas on gas-solid flows in a circulating fluidized bed (CFB) reactor using full-loop numerical simulation

International Journal of Chemical Reactor Engineering ◽

10.1515/ijcre-2020-0119 ◽

2020 ◽

Vol 0 (0) ◽

Author(s):

Pengju Huo ◽

Xiaohong Li ◽

Yang Liu ◽

Haiying Qi

Keyword(s):

Numerical Simulation ◽

Flow Rate ◽

Gas Flow ◽

Circulating Fluidized Bed ◽

Separation Efficiency ◽

Circulation Rate ◽

Solid Mass ◽

Gas Flow Rate ◽

Gas Leakage ◽

Mass Circulation

AbstractThe influences of loose gas on gas-solid flows in a large-scale circulating fluidized bed (CFB) gasification reactor were investigated using full-loop numerical simulation. The two-fluid model was coupled with the QC-energy minimization in multi-scale theory (EMMS) gas-solid drag model to simulate the fluidization in the CFB reactor. Effects of the loose gas flow rate, Q, on the solid mass circulation rate and the cyclone separation efficiency were analyzed. The study found different effects depending on Q: First, the particles in the loop seal and the standpipe tended to become more densely packed with decreasing loose gas flow rate, leading to the reduction in the overall circulation rate. The minimum Q that can affect the solid mass circulation rate is about 2.5% of the fluidized gas flow rate. Second, the sealing gas capability of the particles is enhanced as the loose gas flow rate decreases, which reduces the gas leakage into the cyclones and improves their separation efficiency. The best loose gas flow rates are equal to 2.5% of the fluidized gas flow rate at the various supply positions. In addition, the cyclone separation efficiency is correlated with the gas leakage to predict the separation efficiency during industrial operation.

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Numerical Simulation of the Performance of an Axial Compressor Operating With Supercritical Carbon Dioxide

Volume 8: Computational Fluid Dynamics (CFD); Nuclear Education and Public Acceptance ◽

10.1115/icone26-81573 ◽

2018 ◽

Author(s):

Jinlan Gou ◽

Wei Wang ◽

Can Ma ◽

Yong Li ◽

Yuansheng Lin ◽

...

Keyword(s):

Carbon Dioxide ◽

Numerical Simulation ◽

Supercritical Carbon Dioxide ◽

Critical Point ◽

Mass Flow Rate ◽

Mass Flow ◽

Flow Rate ◽

Axial Compressor ◽

Brayton Cycle ◽

Supercritical Carbon

Using supercritical carbon dioxide (SCO2) as the working fluid of a closed Brayton cycle gas turbine is widely recognized nowadays, because of its compact layout and high efficiency for modest turbine inlet temperature. It is an attractive option for geothermal, nuclear and solar energy conversion. Compressor is one of the key components for the supercritical carbon dioxide Brayton cycle. With established or developing small power supercritical carbon dioxide test loop, centrifugal compressor with small mass flow rate is mainly investigated and manufactured in the literature; however, nuclear energy conversion contains more power, and axial compressor is preferred to provide SCO2 compression with larger mass flow rate which is less studied in the literature. The performance of the axial supercritical carbon dioxide compressor is investigated in the current work. An axial supercritical carbon dioxide compressor with mass flow rate of 1000kg/s is designed. The thermodynamic region of the carbon dioxide is slightly above the vapor-liquid critical point with inlet total temperature 310K and total pressure 9MPa. Numerical simulation is then conducted to assess this axial compressor with look-up table adopted to handle the nonlinear variation property of supercritical carbon dioxide near the critical point. The results show that the performance of the design point of the designed axial compressor matches the primary target. Small corner separation occurs near the hub, and the flow motion of the tip leakage fluid is similar with the well-studied air compressor. Violent property variation near the critical point creates troubles for convergence near the stall condition, and the stall mechanism predictions are more difficult for the axial supercritical carbon dioxide compressor.

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Numerical Simulation of Cavitating Flow in a Francis Turbine

Volume 1: Symposia, Parts A and B ◽

10.1115/fedsm2008-55242 ◽

2008 ◽

Cited By ~ 3

Author(s):

Lingjiu Zhou ◽

Zhengwei Wang ◽

Yongyao Luo ◽

Guangjie Peng

Keyword(s):

Numerical Simulation ◽

Transport Equation ◽

Flow Rate ◽

Suction Side ◽

Cavitating Flow ◽

Francis Turbine ◽

Efficiency Change ◽

Experiment Data ◽

Calculation Results ◽

Vapor Fraction

The 3-D unsteady Reynolds averaged Navier-tokes equations based on the pseudo-homogeneous flow theory and a vapor fraction transport-equation that accounts for non-condensable gas are solved to simulate cavitating flow in a Francis turbine. The calculation results agreed with experiment data reasonably. With the decrease of the Thoma number, the cavity first appears near the centre of the hub. At this stage the flow rate and the efficiency change little. Then the cavity near the centre of the hub grows thick and the cavities also appear on the blade suction side near outlet. With further reduce of the Thoma number the cavitation extends to the whole flow path, which causes flow rate and efficiency decrease rapidly.

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Numerical Simulation of Gas-Liquid Two-Phase Flows on Wetted Walls

ASME 2010 3rd Joint US-European Fluids Engineering Summer Meeting: Volume 1, Symposia – Parts A, B, and C ◽

10.1115/fedsm-icnmm2010-31249 ◽

2010 ◽

Author(s):

Yoshiyuki Iso ◽

Xi Chen

Keyword(s):

Numerical Simulation ◽

Flow Rate ◽

Liquid Flow ◽

Film Flow ◽

Liquid Flow Rate ◽

Flow Transition ◽

Wall Surface ◽

Two Phase ◽

Wall Flows ◽

Rivulet Flow

Gas-liquid two-phase flows on the wall like liquid film flows, which are the so-called wetted wall flows, are observed in many industrial processes such as absorption, desorption, distillation and others. For the optimum design of packed columns widely used in those kind of processes, the accurate predictions of the details on the wetted wall flow behavior in packing elements are important, especially in order to enhance the mass transfer between the gas and liquid and to prevent flooding and channeling of the liquid flow. The present study focused on the effects of the change of liquid flow rate and the wall surface texture treatments on the characteristics of wetted wall flows which have the drastic flow transition between the film flow and rivulet flow. In this paper, the three-dimensional gas-liquid two-phase flow simulation by using the volume of fluid (VOF) model is applied into wetted wall flows. Firstly, as one of new interesting findings in this paper, present results showed that the hysteresis of the flow transition between the film flow and rivulet flow arose against the increasing or decreasing stages of the liquid flow rate. It was supposed that this transition phenomenon depends on the history of flow pattern as the change of curvature of interphase surface which leads to the surface tension. Additionally, the applicability and accuracy of the present numerical simulation were validated by using the existing experimental and theoretical studies with smooth wall surface. Secondary, referring to the texture geometry used in an industrial packing element, the present simulations showed that surface texture treatments added on the wall can improve the prevention of liquid channeling and can increase the wetted area.

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