scholarly journals Three-Dimensional Turbulence Numerical Simulation of Flow in a Stepped Dropshaft

Water ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 30 ◽  
Author(s):  
Yongfei Qi ◽  
Yurong Wang ◽  
Jianmin Zhang
Keyword(s):  
Flow Pattern ◽  
Water Depth ◽  
Three Dimensional ◽  
Drainage System ◽  
Urban Drainage ◽  
Pipe Network ◽  
Central Angle ◽  
Relative Water ◽  
Maximum Water ◽  
Horizontal Step

The dropshaft structure is usually applied in an urban drainage system to connect the shallow pipe network and the deep tunnel. By using the renormalization group (RNG) k~ε turbulence model with a volume of fluid method, the flow pattern and the maximum relative water depth over a stepped dropshaft with a different central angle of step were numerically investigated. The calculated results suggested that the flow in the stepped dropshaft was highly turbulent and characterized by deflection during the jet caused by the curvature of the sidewall. According to the pressure distribution on the horizontal step and the flow pattern above the step, the flow field was partitioned into the recirculating region, the wall-impinging region and the mixing region. In addition, with the increase in the central angle of step, the scope of the wall-impinging region and the mixing region increased and the scope of the recirculating region remained nearly unchanged. The maximum water depth increased with the increase in discharge. In the present work we have shown that, as the value of the central angle of step increased, the maximum water depth decreased initially and increased subsequently.

scholarly journals Diagnose Urban Drainage Network Problem Based on Internet of Things and Big Data

2018 ◽  
Vol 246 ◽  
pp. 02024
Author(s):  
Xiaobo Miao ◽  
Mou Lv ◽  
Fengchao Liang ◽  
Chunjiao Jiao ◽  
Luohua Wang
Keyword(s):  
Big Data ◽  
Internet Of Things ◽  
Drainage System ◽  
Research Area ◽  
Monitoring Data ◽  
Urban Drainage ◽  
Drainage Network ◽  
Pipe Network ◽  
Technical Problems ◽  
Network Problem

Urban drainage pipe network is an important foundation project in urban construction. It has a vital impact on urban waterlogging prevention and water pollution. However, in the current practice, there are many hidden problems in the pipe network, and it is difficult to check the pipe network problem, which restricts the understanding of the drainage system problem to a certain extent. In order to solve the two technical problems of drainage network survey and data statistics, the monitoring technology based on Internet of things and big data is adopted in this study. Taking the sponge city pilot area of a coastal city in China as the research area, the monitoring scheme was established and the monitoring data were obtained. Based on more than 6 million monitoring data, the automatic analysis algorithm is applied to analyse the problems of mixed connection of rain and sewage and tidal backwater in the pipeline network. The results show that there are a total of 17 outlets in 160 outlets with problems of rain and sewage mixing. Among them, there are four outlets with regular domestic sewage entering the rainwater pipe network, 7 outlets with irregular sewage entering the rainwater pipe network, and 6 outlets where sewage is smuggled into the rainwater pipe network. In addition, there is a sea tidal backwater phenomenon at one of the coastal rainwater outfalls.

Distributed modelling of urban runoff using a meta-channel concept

2010 ◽  
Vol 61 (11) ◽  
pp. 2707-2715 ◽  
Author(s):  
H. Kim ◽  
G. Pak ◽  
H. Jun ◽  
S. Kim ◽  
J. Yoon
Keyword(s):  
Wave Equation ◽  
Drainage System ◽  
Flood Routing ◽  
Urban Drainage ◽  
Two Dimensional ◽  
Pipe Network ◽  
Computational Accuracy ◽  
Diffusion Wave ◽  
Venant Equation ◽  
Urban Catchments

Hydraulic flood routing is advantageous for computational accuracy; however, it requires individual calculations of an extensive pipe network in the case of a two-dimensional analysis. In this study, a method for considering the characteristics of a two-dimensional pipe network has been developed using the meta-channel concept to simplify the detailed calculations involved in the estimation of runoff from urban catchments. In essence, the meta-channel concept turns a two-dimensional pipe network into a one-dimensional pipe with an effective hydraulic geometry. Once such geometry has been identified, the flood routing can then be performed for an urban drainage system. A nonlinear diffusion wave equation, derived from the Saint-Venant equation, was used for flood routing, with an explicit method used for the numerical solution. The celerity and diffusion coefficients, which are two parameters of the diffusion wave equation, were estimated for the Goonja drainage from a two-dimensional pipe network using the meta-channel concept. A comparison of the results of the meta-channel-based pipe routing with the distributed SWMM simulation and observed data, showed close similarities, and identified the applicability of the meta-channel concept in an urban drainage setting.

scholarly journals Coniacian–Santonian Radiolaria from the Upper Cretaceous of Bornholm, Denmark: A preliminary investigation

2005 ◽  
Vol 52 ◽  
pp. 141-158
Author(s):  
Stephen R. Packer ◽  
Malcolm B. Hart
Keyword(s):  
Late Cretaceous ◽  
Water Depth ◽  
Upper Cretaceous ◽  
Preliminary Investigation ◽  
Poor Recovery ◽  
Relative Water ◽  
Maximum Water ◽  
Abundance And Diversity ◽  
First Time

A moderately diverse fauna of Late Cretaceous Radiolaria are described for the first time from the Arnager Limestone and Bavnodde Greensand formations exposed on the island of Bornholm (Denmark). Our preliminary investigation suggests that the fauna from the Arnager Limestone Formation is relatively abundant and is assigned to the Orbiculiforma vacaensis Subzone (Alievium praegallowayi Zone) of Coniacian age. Relatively poor recovery from the Bavnodde Greensand Formation precludes assignment to the zonation scheme of Pessagno, although, the radiolarian taxa present indicate that the formation can be no younger than Santonian. The ages given for both formations by the radiolarian faunas compare favourably with published macrofossil and microfossil data. The radiolarian faunas described are of moderate abundance and diversity when compared to contemporaneous faunas described elsewhere, particularly the Tethyan area. Maximum radiolarian abundance and diversity is reached in the middle of the Arnager Limestone Formation equating to a level of maximum water depth from the foraminiferal data. A decline in radiolarian recovery is recognised into the Bavnodde Greensand Formation and is associated with a reduction in relative water depth to inner and (?)middle shelf conditions, as indicated by foraminiferal data.

Studies on the Integration of Geographic Information System (GIS) and Drainage Pipe Network Model

2011 ◽  
Vol 317-319 ◽  
pp. 1749-1754
Author(s):  
Yu Fang Tang ◽  
Hong Hu Zeng ◽  
Chang Wen Lei ◽  
Di Na Tan ◽  
Bao Liang Wang ◽  
...  
Keyword(s):  
Information System ◽  
Geographic Information System ◽  
Network Model ◽  
Calculation Method ◽  
Drainage System ◽  
System Model ◽  
System Management ◽  
Urban Drainage ◽  
Pipe Network ◽  
Drainage Pipe

With the development of the simulative theory and calculation method of drainage pipe network, urban drainage pipe network model gradually become an indispensable part of the urban drainage system management. The characteristics of modern drainage pipelines,the content of drainage pipelines system model, the problems of combining GIS with drainage pipelines and how to solve them are briefly described in this paper.

Comprehensive Planning of Urban Drainage and Wastewater Treatment

1993 ◽  
Vol 27 (12) ◽  
pp. 205-208
Author(s):  
Dirk-Th Kollatsch
Keyword(s):  
Wastewater Treatment ◽  
Transport Model ◽  
Drainage System ◽  
Simulation Models ◽  
Urban Drainage ◽  
Sewer Systems ◽  
Priority Task ◽  
Treatment Facilities ◽  
Receiving Waters ◽  
Pollution Impacts

For upgrading the urban drainage system (UDS) the reduction of pollution impacts is the priority task concerning the environmental protection of the receiving waters. With simulation models the interactions between surface, sewer systems, overflow structures and treatment facilities within the UDS can be shown. Models to simulate the pollutant impacts, transport and the effects on the receiving waters are available. In a first step a pollutant transport model of sewer systems and a model to simulate the wastewater treatment processes are connected. With these models the efficiency of upgrading measures can be checked in all parts of urban drainage systems.

A novel approach to the real-time modelling of large urban drainage systems

1997 ◽  
Vol 36 (8-9) ◽  
pp. 19-24 ◽  
Author(s):  
Richard Norreys ◽  
Ian Cluckie
Keyword(s):  
Real Time ◽  
Dynamic Models ◽  
Drainage System ◽  
Radar Data ◽  
Urban Drainage ◽  
Real Time Control ◽  
Empirical Modelling ◽  
Time Control ◽  
Novel Approach ◽  
Non Linear Systems

Conventional UDS models are mechanistic which though appropriate for design purposes are less well suited to real-time control because they are slow running, difficult to calibrate, difficult to re-calibrate in real time and have trouble handling noisy data. At Salford University a novel hybrid of dynamic and empirical modelling has been developed, to combine the speed of the empirical model with the ability to simulate complex and non-linear systems of the mechanistic/dynamic models. This paper details the ‘knowledge acquisition module’ software and how it has been applied to construct a model of a large urban drainage system. The paper goes on to detail how the model has been linked with real-time radar data inputs from the MARS c-band radar.

scholarly journals A Low-Cost Water Depth and Electrical Conductivity Sensor for Detecting Inputs into Urban Stormwater Networks

Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 3056
Author(s):  
Baiqian Shi ◽  
Stephen Catsamas ◽  
Peter Kolotelo ◽  
Miao Wang ◽  
Anna Lintern ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Water Depth ◽  
Asset Management ◽  
Low Cost ◽  
Rate Of Change ◽  
Urban Drainage ◽  
Urban Stormwater ◽  
High Resolution Data ◽  
Conductivity Sensor ◽  
Level Sensor

High-resolution data collection of the urban stormwater network is crucial for future asset management and illicit discharge detection, but often too expensive as sensors and ongoing frequent maintenance works are not affordable. We developed an integrated water depth, electrical conductivity (EC), and temperature sensor that is inexpensive (USD 25), low power, and easily implemented in urban drainage networks. Our low-cost sensor reliably measures the rate-of-change of water level without any re-calibration by comparing with industry-standard instruments such as HACH and HORIBA’s probes. To overcome the observed drift of level sensors, we developed an automated re-calibration approach, which significantly improved its accuracy. For applications like monitoring stormwater drains, such an approach will make higher-resolution sensing feasible from the budget control considerations, since the regular sensor re-calibration will no longer be required. For other applications like monitoring wetlands or wastewater networks, a manual re-calibration every two weeks is required to limit the sensor’s inaccuracies to ±10 mm. Apart from only being used as a calibrator for the level sensor, the conductivity sensor in this study adequately monitored EC between 0 and 10 mS/cm with a 17% relative uncertainty, which is sufficient for stormwater monitoring, especially for real-time detection of poor stormwater quality inputs. Overall, our proposed sensor can be rapidly and densely deployed in the urban drainage network for revolutionised high-density monitoring that cannot be achieved before with high-end loggers and sensors.

Integrated modelling: comparison of state variables, processes and parameters in sewer and wastewater treatment plant models

1997 ◽  
Vol 36 (5) ◽  
pp. 373-380 ◽  
Author(s):  
C. Fronteau ◽  
W. Bauwens ◽  
P.A. Vanrolleghem
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Drainage System ◽  
Integrated Modelling ◽  
Urban Drainage ◽  
State Variables ◽  
Sewer System ◽  
Wastewater Treatment Process ◽  
Urban Drainage System

All the parts of an urban drainage system, i.e. the sewer system, the wastewater treatment plant (WWTP) and the river, should be integrated into one single model to assess the performance of the overall system and for the development of design and control strategies assisting in its sustainable and cost effective management. Existing models for the individual components of the system have to be merged in order to develop the integrated tool. One of the problems arising from this methodology is the incompatibility of state variables, processes and parameters used in the different modelling approaches. Optimisation of an urban drainage system, and of the wastewater treatment process in particular, requires a good knowledge of the wastewater composition. As important transformations take place between the emission from the household and the arrival at the treatment facility, sewer models should include these transformations in the sewer system. At present, however, research is still needed in order to increase our knowledge of these in-sewer processes. A comparison of the state variables, processes and parameters has been carried out in both sewer models (SMs) and activated sludge models (ASMs). An ASM approach is used for the description of reactions in sewer models. However, a difference is found in the expression for organic material (expressed in terms of BOD) and heterotrophic biomass is absent as a state variable, resulting in differences in processes and parameters. Reconciliation of both the models seems worthwhile and a preliminary solution is suggested in this paper.

scholarly journals Modelling Pluvial Flooding in Urban Areas Coupling the Models Iber and SWMM

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2647
Author(s):  
Esteban Sañudo ◽  
Luis Cea ◽  
Jerónimo Puertas
Keyword(s):  
Urban Areas ◽  
Flow Model ◽  
Overland Flow ◽  
Drainage System ◽  
Urban Drainage ◽  
Dynamic Link Library ◽  
Storm Water Management Model ◽  
Urban Street ◽  
Sewer Network ◽  
Overland Flow Model

Dual urban drainage models allow users to simulate pluvial urban flooding by analysing the interaction between the sewer network (minor drainage system) and the overland flow (major drainage system). This work presents a free distribution dual drainage model linking the models Iber and Storm Water Management Model (SWMM), which are a 2D overland flow model and a 1D sewer network model, respectively. The linking methodology consists in a step by step calling process from Iber to a Dynamic-link Library (DLL) that contains the functions in which the SWMM code is split. The work involves the validation of the model in a simplified urban street, in a full-scale urban drainage physical model and in a real urban settlement. The three study cases have been carefully chosen to show and validate the main capabilities of the model. Therefore, the model is developed as a tool that considers the main hydrological and hydraulic processes during a rainfall event in an urban basin, allowing the user to plan, evaluate and design new or existing urban drainage systems in a realistic way.

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