Study of hydraulics and mixing in roof tanks used in intermittent water supply

2016 ◽  
Vol 6 (4) ◽  
pp. 547-554
Author(s):  
R. D. Hernandez-Lopez ◽  
V. G. Tzatchkov ◽  
A. Martin-Dominguez ◽  
V. H. Alcocer-Yamanaka
Keyword(s):  
Water Supply ◽  
Water Demand ◽  
Flow Reactor ◽  
Numerical Models ◽  
Fluid Dynamic ◽  
Distribution Network ◽  
Distribution Model ◽  
Laboratory Model ◽  
Dynamic Simulations ◽  
Intermittent Water Supply

Roof tanks are common in low and middle income countries, due to the intermittent water supply. Their hydraulic and water mixing behaviour has not been studied. This paper presents the results of a study on mixing and water demand in roof tanks, based on physical and numerical models. Tracer tests were carried out on a real scale transparent wall laboratory model of a roof tank, and a three-parameter residence time distribution model was applied, showing that the model that best describes mixing in roof water tanks is the one with a completely stirred flow reactor with a small portion of bypassing. This result was confirmed by computational fluid dynamic simulations and visual observation. The instantaneous water flow derived from activating typical home water-using fixtures was measured at the pipe feeding the tank, the pipe exiting the tank, and without a roof tank. Stochastic water demand patterns were generated with the measured data and used in the numerical model of a small distribution network. Based on this model it was found that water demand and pipe flow behave differently in continuous and intermittent water supply networks. The instantaneous flow rate withdrawn from the water distribution network pipes is lower in systems with roof tanks.

scholarly journals <i>HydrothermalFoam</i> v1.0: a 3-D hydrothermal transport model for natural submarine hydrothermal systems

2020 ◽  
Vol 13 (12) ◽  
pp. 6547-6565
Author(s):  
Zhikui Guo ◽  
Lars Rüpke ◽  
Chunhui Tao
Keyword(s):  
Transport Model ◽  
Numerical Models ◽  
Fluid Dynamic ◽  
Pure Water ◽  
Three Dimensional ◽  
Hydrothermal Systems ◽  
Dynamic Simulations ◽  
Flow Models ◽  
Wide Range ◽  
Submarine Hydrothermal Systems

Abstract. Herein, we introduce HydrothermalFoam, a three-dimensional hydro-thermo-transport model designed to resolve fluid flow within submarine hydrothermal circulation systems. HydrothermalFoam has been developed on the OpenFOAM platform, which is a finite-volume-based C++ toolbox for fluid-dynamic simulations and for developing customized numerical models that provides access to state-of-the-art parallelized solvers and to a wide range of pre- and post-processing tools. We have implemented a porous media Darcy flow model with associated boundary conditions designed to facilitate numerical simulations of submarine hydrothermal systems. The current implementation is valid for single-phase fluid states and uses a pure-water equation of state (IAPWS-97). We here present the model formulation; OpenFOAM implementation details; and a sequence of 1-D, 2-D, and 3-D benchmark tests. The source code repository further includes a number of tutorials that can be used as starting points for building specialized hydrothermal flow models. The model is published under the GNU General Public License v3.0.

scholarly journals <i>HydrothermalFoam</i> v1.0: a 3-D hydro-thermo-transport model for natural submarine hydrothermal systems

2020 ◽  
Author(s):  
Zhikui Guo ◽  
Lars Rüpke ◽  
Chunhui Tao
Keyword(s):  
Transport Model ◽  
Numerical Models ◽  
Fluid Dynamic ◽  
Pure Water ◽  
Three Dimensional ◽  
Hydrothermal Systems ◽  
Dynamic Simulations ◽  
Flow Models ◽  
Wide Range ◽  
Submarine Hydrothermal Systems

Abstract. Herein, we introduce HydrothermalFoam, a three dimensional hydro-thermo-transport model designed to resolve fluid flow within submarine hydrothermal circulation systems. HydrothermalFoam has been developed on the OpenFOAM platform, which is a Finite Volume based C++ toolbox for fluid-dynamic simulations and for developing customized numerical models that provides access to state-of-the-art parallelized solvers and to a wide range of pre- and post-processing tools. We have implemented a porous media Darcy-flow model with associated boundary conditions designed to facilitate numerical simulations of submarine hydrothermal systems. The current implementation is valid for single-phase fluid states and uses a pure water equation-of-state (IAPWS-97). We here present the model formulation, OpenFOAM implementation details, and a sequence of 1-D, 2-D and 3-D benchmark tests. The source code repository further includes a number of tutorials that can be used as starting points for building specialized hydrothermal flow models. The model is published under the GNU General Public License v3.0.

A GIS-based water distribution model for Zhengzhou city, China

2011 ◽  
Vol 11 (4) ◽  
pp. 497-503 ◽  
Author(s):  
Hou Yu-Kun ◽  
Zhao Chun-Hui ◽  
Huang Yu-Chung
Keyword(s):  
Water Supply ◽  
Distribution System ◽  
Water Distribution ◽  
Distribution Network ◽  
Water Distribution Network ◽  
Hydraulic Model ◽  
Distribution Model ◽  
Roughness Coefficient ◽  
Model Parameters ◽  
Pipe Roughness

Many water companies in China are developing GIS as a computer-based tool, for mapping and analyzing objects and events that happen on a water distribution network. However, only a few companies have taken a further step to develop a hydraulic model based on GIS, and Zhengzhou Water Supply Corporation is one of them. The WaterGEMS V8 XM from Bentley is used to develop the hydraulic model for the water distribution network in Zhengzhou city, which has a population of over 3 million. During establishment of the model, some of the data extracted from GIS are missing, abnormal, and redundant and require careful screening, searching, and judging. Model calibration is performed after a sensitivity analysis. Peaking factor and pipe roughness coefficient are key model parameters to calibrate. In calibrating peaking factors, the distribution system is divided into 5 operation districts with different types of water usage. To calibrate pipe roughness coefficients, the system was divided into 4 water supply districts with different attributes of pipelines. Finally, a case study of pipe layout evaluation it shows the hydraulic model to be a powerful tool for water supply management.

scholarly journals Research on Optimal Allocation of Regional Annual Water Consumption

2015 ◽  
Vol 9 (1) ◽  
pp. 743-750
Author(s):  
Xianqi Zhang
Keyword(s):  
Water Supply ◽  
Water Consumption ◽  
Water Demand ◽  
Water Distribution ◽  
Optimal Allocation ◽  
Research Result ◽  
Distribution Model ◽  
Optimal Distribution ◽  
Distribution Method ◽  
Regional Water

The optimization of regional water distribution refers to distributing regional and industrial water supply scientifically on the premises of limited regional water supply with an excess of demand for the purpose of fulfilling every industry’s water supply. The study treats the optimal distribution of annual regional water consumption as a systematic dynamic optimization and analyzes its optimizing process, procedure and basic form of its models. The study constructs a regional water consumption system and raises a model to optimize regional water allocation that focuses on the water consumption standard of many categories, including living water, farm irrigation, forestry, animal husbandry, fishery livestock, industry, the public and environmental water demand of the city. Aiming at achieving the maximum comprehensive benefits of regional water consumption when dealing with its structure and habits, the optimal distribution model of regional water is devised after adopting the dynamic optimized distribution method to optimize the regional water consumption. As is shown by the research result, when applied to the regional water distribution optimization, this model can well optimize the distribution in every region and industry. It can thus coordinate among every system of water demand and supply in every region. This project study is significantly meaningful to ensure the scientific and reasonable water use in a region. It is also crucial to the sustainable utilization of water and sustainable development of society.

STUDYING OF WATERHAMMER PHENOMENON CAUSED BY SUDDEN VARIATION OF WATER DEMAND AT WATER SUPPLY PIPES NETWORK

2012 ◽  
Vol 40 (2) ◽  
pp. 353-366
Author(s):  
Gamal Abozaid ◽  
Hassan I. Mohammed ◽  
Hassan I. Mostafa
Keyword(s):  
Water Supply ◽  
Water Demand

Investigating artificial groundwater recharge to ensure the water supply to the city of Graz

2008 ◽  
Vol 3 (3) ◽  
Author(s):  
Wilhelm Tischendorf ◽  
Hans Kupfersberger ◽  
Christian Schilling ◽  
Oliver Gabriel
Keyword(s):  
Water Supply ◽  
Groundwater Recharge ◽  
Water Demand ◽  
Bulk Water ◽  
Retention Rates ◽  
Subsurface Water ◽  
Artificial Groundwater Recharge ◽  
Advantages And Disadvantages ◽  
Water Recharge ◽  
Water Supply Company

Being Austria's fourth largest water-supply company, the Grazer Stadtwerke AG., has ensured the successful water-supply of the Styrian capital with 250.000 inhabitants for many years. The average daily water demand of the area amounts to about 50,000 m3. Approximately 30 % of the total demand is covered by the bulk water supply from the Zentral Wasser Versorgung Hochschwab Süd. The waterworks Friesach and Andritz, which cover the additional 70 % of the water demand, operate by means of artificial groundwater recharge plants where horizontal filter wells serve as drawing shafts. The groundwater recharge systems serve to increase the productivity of the aquifer and to reduce the share of the infiltration from the Mur River. Protection areas have been identified to ensure that the water quality of the aquifer stay at optimal levels. The protection areas are divided into zones indicating various restrictions for usage and planning. Two respective streams serve as the source for the water recharge plants. Different infiltration systems are utilised. Each of the various artificial groundwater recharge systems displays specific advantages and disadvantages in terms of operation as well as maintenance. In order to secure a sustainable drinking water supply the recharge capacity will be increased. Within an experimental setting different mixtures of top soils are investigated with respect to infiltration and retention rates and compared to the characteristics of the existing basins. It can be shown that the current operating sand basin with more than 90% grains in the range between 0.063 and 6.3 mm represents the best combination of infiltration and retention rates. In future experiments the performance of alternative grain size distributions as well as planting the top soil will be tested. Additionally, in order to optimize the additional groundwater recharge structures the composition of the subsurface water regarding its origin is statistically analyzed.

A study on appropriate investment of pipeline rehabilitation for water distribution network

2005 ◽  
Vol 5 (2) ◽  
pp. 31-38
Author(s):  
A. Asakura ◽  
A. Koizumi ◽  
O. Odanagi ◽  
H. Watanabe ◽  
T. Inakazu
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Water Supply ◽  
Water Distribution ◽  
Ad Hoc ◽  
Distribution Network ◽  
Water Distribution Network ◽  
Distribution Networks ◽  
Optimal Basis ◽  
Model Case

In Japan most of the water distribution networks were constructed during the 1960s to 1970s. Since these pipelines were used for a long period, pipeline rehabilitation is necessary to maintain water supply. Although investment for pipeline rehabilitation has to be planned in terms of cost-effectiveness, no standard method has been established because pipelines were replaced on emergency and ad hoc basis in the past. In this paper, a method to determine the maintenance of the water supply on an optimal basis with a fixed budget for a water distribution network is proposed. Firstly, a method to quantify the benefits of pipeline rehabilitation is examined. Secondly, two models using Integer Programming and Monte Carlo simulation to maximize the benefits of pipeline rehabilitation with limited budget were considered, and they are applied to a model case and a case study. Based on these studies, it is concluded that the Monte Carlo simulation model to calculate the appropriate investment for the pipeline rehabilitation planning is both convenient and practical.

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