scholarly journals Flow modeling and analysis of compound channel in river network with complex floodplains and groynes

2010 ◽  
Vol 13 (3) ◽  
pp. 474-488 ◽  
Author(s):  
Hassan Ahmed ◽  
Norio Tanaka ◽  
Nobuyuki Tamai
Keyword(s):  
Water Depth ◽  
River Flow ◽  
Storage Capacity ◽  
Flow Simulation ◽  
Two Dimensional ◽  
Compound Channel ◽  
Modeling And Analysis ◽  
Flow Models ◽  
Flow Simulations ◽  
Kanto Region

Presented here are flow simulations of a network of natural rivers flanked by one or two large and complex floodplains with impermeable groynes and bridge embankments using one- and quasi-two-dimensional dynamic flow models. The effects of the large floodplain storage capacity, momentum transfer interaction and apparent shear stress at the vertical interface between the main channel and floodplain on the flow-simulated discharge and water depth values could be well explained. The two models were tested and validated in the Arakawa River basin, Kanto Region, Japan. The simulated results show that the large floodplain storage capacity greatly affected the flow discharge and water depth results and cannot be neglected. The quasi-two-dimensional river flow model was used in a flow simulation of a compound channel with complex floodplains with groynes and gave more acceptable results. In the simulated case, the average reduction in flood discharge using floodplain groynes was about 7–15%. Thus, floodplain groynes can be effective for flood protection and attenuation.

scholarly journals A Momentum-Conserving Scheme for Flow Simulation in 1D Channel with Obstacle and Contraction

Fluids ◽  
2021 ◽  
Vol 6 (1) ◽  
pp. 26
Author(s):  
Putu Veri Swastika ◽  
Sri Redjeki Pudjaprasetya ◽  
Leo Hari Wiryanto ◽  
Revi Nurfathhiyah Hadiarti
Keyword(s):  
River Flow ◽  
Flow Simulation ◽  
Staggered Grid ◽  
Steady Flows ◽  
Flow Modeling ◽  
Dimensional Approach ◽  
Flow Simulations ◽  
Saint Venant Equations ◽  
Steady Solutions ◽  
Good Agreement

We consider the extension of the momentum conservative staggered-grid (MCS) scheme for flow simulation in channels with varying depth and width. The scheme is formulated using the conservative properties of the Saint-Venant equations. The proposed scheme was successful in handling various steady flows and achieved results that are in complete accordance with the analytical steady solutions. Different choices of boundary conditions have created steady solutions according to the mass and energy conservations. This assessment has served as a validation of the proposed numerical scheme. Further, in a channel with a contraction and a nonuniform bed, we simulate two cases of dam break. The simulation results show a good agreement with existing experimental data. Moreover, our scheme, that uses a quasi-1-dimensional approach, has shown some fair agreement with existing 2-dimensional numerical results. This evaluation demonstrates the merits of the MCS scheme for various flow simulations in channels of varying width and bathymetry, suitable for river flow modeling.

Feasibility Study of a Subsea to Shore Production System

2016 ◽  
Author(s):  
Anna Carolinna Carrano Porto Scudino Alves ◽  
Ilson Paranhos Pasqualino
Keyword(s):  
Comparative Study ◽  
Feasibility Study ◽  
Water Depth ◽  
Production System ◽  
Flow Simulation ◽  
Light Water ◽  
Flow Simulations ◽  
Heavy Medium ◽  
Oil Density ◽  
Oil Type

This work develops a technical and economic comparative study between a scenario with exploitation using stationary production units and a scenario with subsea to shore. Moreover, evaluates the subsea to shore scenario varying parameters of oil type (heavy, medium and light), water depth (80 m, 500 m 1000 m) and distance to the coast (50 km and 100 km), aiming the optimization of the subsea equipment for the different scenarios created from the combination of the three parameters mentioned above and the flow simulation success. A pilot field was designed for this study and used in the flow simulations performed. The results corroborate with the difficulties of flowing expected with the increase of the water depth and the distance to the coast and decrease of the oil density.

Agent-Based Modelling Simulation Case Study: Assessment of Airport Check-In and Evacuation Process by Considering Group Travel Behaviour of Air Passengers

2014 ◽  
Vol 568-570 ◽  
pp. 1859-1864
Author(s):  
Lin Cheng ◽  
Vikas Reddy ◽  
Clinton Fookes ◽  
Prasad K.D.V. Yarlagadda
Keyword(s):  
Group Dynamics ◽  
Flow Simulation ◽  
Travel Behaviour ◽  
Agent Based ◽  
Flow Models ◽  
Flow Simulations ◽  
Passenger Flow ◽  
Airport Terminals ◽  
Group Travel

Passenger experience has become a major factor that influences the success of an airport. In this context, passenger flow simulation has been used in designing and managing airports. However, most passenger flow simulations failed to consider the group dynamics when developing passenger flow models. In this paper, an agent-based model is presented to simulate passenger behaviour at the airport check-in and evacuation process. The simulation results show that the passenger behaviour can have significant influences on the performance and utilisation of services in airport terminals. The model was created using AnyLogic software and its parameters were initialised using recent research data published in the literature.

scholarly journals INFLUENCE OF RIVER BED ELEVATION SURVEY CONFIGURATIONS AND INTERPOLATION METHODS ON THE ACCURACY OF LIDAR DTM-BASED RIVER FLOW SIMULATIONS

2016 ◽  
Vol XLII-4/W1 ◽  
pp. 225-235 ◽  
Author(s):  
J. R. Santillan ◽  
J. L. Serviano ◽  
M. Makinano-Santillan ◽  
J. T. Marqueso
Keyword(s):  
River Flow ◽  
Interpolation Method ◽  
Flow Simulation ◽  
Flow Simulations ◽  
Bed Elevation ◽  
River Bed ◽  
Elevation Data ◽  
Data Points ◽  
Simulation Results ◽  
River Flow Simulation

In this paper, we investigated how survey configuration and the type of interpolation method can affect the accuracy of river flow simulations that utilize LIDAR DTM integrated with interpolated river bed as its main source of topographic information. Aside from determining the accuracy of the individually-generated river bed topographies, we also assessed the overall accuracy of the river flow simulations in terms of maximum flood depth and extent. Four survey configurations consisting of river bed elevation data points arranged as cross-section (XS), zig-zag (ZZ), river banks-centerline (RBCL), and river banks-centerline-zig-zag (RBCLZZ), and two interpolation methods (Inverse Distance-Weighted and Ordinary Kriging) were considered. Major results show that the choice of survey configuration, rather than the interpolation method, has significant effect on the accuracy of interpolated river bed surfaces, and subsequently on the accuracy of river flow simulations. The RMSEs of the interpolated surfaces and the model results vary from one configuration to another, and depends on how each configuration evenly collects river bed elevation data points. The large RMSEs for the RBCL configuration and the low RMSEs for the XS configuration confirm that as the data points become evenly spaced and cover more portions of the river, the resulting interpolated surface and the river flow simulation where it was used also become more accurate. The XS configuration with Ordinary Kriging (OK) as interpolation method provided the best river bed interpolation and river flow simulation results. The RBCL configuration, regardless of the interpolation algorithm used, resulted to least accurate river bed surfaces and simulation results. Based on the accuracy analysis, the use of XS configuration to collect river bed data points and applying the OK method to interpolate the river bed topography are the best methods to use to produce satisfactory river flow simulation outputs. The use of other configurations (and a choice between IDW or OK) except RBCL can also be an alternative in cases when the XS configuration is less practical or expensive to implement.

scholarly journals Hydraulic Evaluation of the Levee System Evolution on the Kurobe Alluvial Fan in the 18th and 19th Centuries

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4406
Author(s):  
Tadaharu Ishikawa ◽  
Hiroshi Senoo
Keyword(s):  
Channel Capacity ◽  
Flood Control ◽  
River Flow ◽  
Global Climate ◽  
Flow Simulation ◽  
Japan Sea ◽  
Main Channel ◽  
Alluvial Fan ◽  
Flood Peak ◽  
Levee System

The development process and flood control effects of the open-levee system, which was constructed from the mid-18th to the mid-19th centuries, on the Kurobe Alluvial Fan—a large alluvial fan located on the Japan Sea Coast of Japan’s main island—was evaluated using numerical flow simulation. The topography for the numerical simulation was determined from an old pictorial map in the 18th century and various maps after the 19th century, and the return period of the flood hydrograph was determined to be 10 years judging from the level of civil engineering of those days. The numerical results suggested the followings: The levees at the first stage were made to block the dominant divergent streams to gather the river flows together efficiently; by the completed open-levee system, excess river flow over the main channel capacity was discharged through upstream levee openings to old stream courses which were used as temporary floodways, and after the flood peak, a part of the flooded water returned to the main channel through the downstream levee openings. It is considered that the ideas of civil engineers of those days to control the floods exceeding river channel capacity, embodied in their levee arrangement, will give us hints on how to control the extraordinary floods that we should face in the near future when the scale of storms will increase due to the global climate change.

scholarly journals On the Scope of Lagrangian Vortex Methods for Two-Dimensional Flow Simulations and the POD Technique Application for Data Storing and Analyzing

Entropy ◽  
2021 ◽  
Vol 23 (1) ◽  
pp. 118
Author(s):  
Kseniia Kuzmina ◽  
Ilia Marchevsky ◽  
Irina Soldatova ◽  
Yulia Izmailova
Keyword(s):  
Flow Simulation ◽  
Internal Flow ◽  
Reynolds Numbers ◽  
Circular Cylinders ◽  
Vortex Methods ◽  
Flow Simulations ◽  
Additional Information ◽  
Two Dimensional Flow ◽  
Different Shapes ◽  
Problem Formulations

The possibilities of applying the pure Lagrangian vortex methods of computational fluid dynamics to viscous incompressible flow simulations are considered in relation to various problem formulations. The modification of vortex methods—the Viscous Vortex Domain method—is used which is implemented in the VM2D code developed by the authors. Problems of flow simulation around airfoils with different shapes at various Reynolds numbers are considered: the Blasius problem, the flow around circular cylinders at different Reynolds numbers, the flow around a wing airfoil at the Reynolds numbers 104 and 105, the flow around two closely spaced circular cylinders and the flow around rectangular airfoils with a different chord to the thickness ratio. In addition, the problem of the internal flow modeling in the channel with a backward-facing step is considered. To store the results of the calculations, the POD technique is used, which, in addition, allows one to investigate the structure of the flow and obtain some additional information about the properties of flow regimes.

Research on the Pollution Diffusion Regularity near Sewage Outlet Areas in Yuncheng Reach of the Fen River

2011 ◽  
Vol 383-390 ◽  
pp. 2430-2436
Author(s):  
Jian Hua Hou ◽  
Min Quan Feng ◽  
Xiao Peng Xing ◽  
Zhen Hua Hou
Keyword(s):  
Water Quality ◽  
Flow Field ◽  
Water Depth ◽  
Concentration Gradient ◽  
River Flow ◽  
Measured Data ◽  
Quality Model

The purpose of this paper is to find the pollution diffusion regularity near sewage outlet area of Yuncheng reach of the Fen River. A 2-D water hydrodynamic and quality model was used to simulate flow field, the water quality and contamination dispersion. The parameters of the model were calibrated with measured data of the water depth, flow and water quality in Yuncheng reach of the Fen River. According to the simulated result, the total area of pollution belt with 19 sewage outlets is 8.89km2 in normal year. And 3.89% of the reach has a worse water quality than V class in standard. The percentage of V and Ⅳ Class of water is 69.17% and 26.94%.In dry year, the total area of pollution belt with 19 sewage outlets is 8.89km2.The percentage of inferior V, V and Ⅳ Class of water is 27.80%, 69.46% and 2.74%. It was shown by the simulated results that the concentration gradient decreases with increasing distance to the outlets and the dilution and dispersion of pollutants was enhanced by a greater river flow.

River parametrisation of the JULES land surface model for improved runoff routing at the global scale.

2021 ◽  
Author(s):  
Aristeidis Koutroulis ◽  
Manolis Grillakis ◽  
Camilla Mathison ◽  
Eleanor Burke
Keyword(s):  
Spatial Resolution ◽  
Land Surface ◽  
River Flow ◽  
Land Surface Model ◽  
Flow Simulation ◽  
Surface Model ◽  
Routing Scheme ◽  
Basin Scale ◽  
River Flow Simulation ◽  
River Routing

<p>The JULES land surface model has a wide ranging application in studying different processes of the earth system including hydrological modeling [1]. Our aim is to tune the existing configuration of the global river routing scheme at 0.5<sup>o</sup> spatial resolution [2] and improve river flow simulation performance at finer temporal scales. To do so, we develop a factorial experiment of varying effective river velocity and meander coefficient, components of the Total Runoff Integrating Pathways (TRIP) river routing scheme. We test and adjust best performing configurations at the basin scale based on observations from GRDC 230 stations that exhibiting a variety of hydroclimatic and physiographic conditions. The analysis was focused on watersheds of near-natural conditions [3] to avoid potential influences of human management on river flow. The HydroATLAS database [4] was employed to identify basin scale descriptive hydro-environmental indicators that could be associated with the components of the TRIP. These indicators summarize hydrologic and physiographic characteristics of the drainage area of each flow gauge. For each basin we select the best performing set of TRIP parameters per basin resulting to the optimal efficiency of river flow simulation based on the Nash–Sutcliffe and Kling–Gupta efficiency metrics. We find that better performance is driven predominantly by characteristics related to the stream gradient and terrain slope. These indicators can serve as descriptors for extrapolating the adjustment of TRIP parameters for global land configurations at 0.5<sup>o</sup> spatial resolution using regression models.</p><p> </p><p>[1] Papadimitriou et al 2017, Hydrol. Earth Syst. Sci., 21, 4379–4401</p><p>[2] Falloon et al 2007. Hadley Centre Tech. Note 72, 42 pp.</p><p>[3] Fang Zhao et al 2017 Environ. Res. Lett. 12 075003</p><p>[4] Linke et al 2019, Scientific Data 6: 283.</p>

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