scholarly journals A finite element method for environmental and pollutant transport prediction

2019 ◽  
pp. 122-129
Author(s):  
Victorita Radulescu
Keyword(s):  
Numerical Model ◽  
Groundwater Flow ◽  
Pollutant Transport ◽  
Mass Conservation ◽  
Ecological Impacts ◽  
Time Interval ◽  
Flow Equations ◽  
Sources Of Pollution ◽  
Water Quality Trends ◽  
Transport Prediction

In the last decades, significant researches were dedicated to model the water-quality trends, soil erosion and material losses, contaminant transport, and their ecological impacts. The present paper investigates theoretically and presents a numerical model with finite elements of the pollutant transport and diffusion in 2-D environmental flow. It is a general model based on the physical groundwater flow equations presented into a new approach, in quantity structure. The mathematical model is based on mass conservation, including the main flow of the fluid and existing pollutants. The fluid mass conservation includes the changes in the groundwater volume flow in a selected time interval and the appeared modifications in the aquifer characteristics due to the pollutant presence are used in the numerical model. Some supplementary considerations concerning mathematical modeling are briefly presented. This model can be used to simulate the groundwater behavior in different situations, with a concentrated source of the pollutant, or with 2 sources of pollution. In the present paper are simulated only the aquifers with mainly horizontal groundwater flow and with a relatively known aquifer’s structure. The model is tested for a landfill near the Dambovita River, to predict the groundwater contamination and the time variation of concentration. Finally, some conclusions and references are presented.

scholarly journals Groundwater Flow Modeling in Chitwan Dun Valley (Between Narayani River and Lothar Khola), Nepal

2019 ◽  
Vol 24 (2) ◽  
pp. 30-38
Author(s):  
Rita Bhandari ◽  
Dinesh Pathak
Keyword(s):  
Numerical Model ◽  
Groundwater Flow ◽  
Groundwater Modeling ◽  
Flow Direction ◽  
Flow Modeling ◽  
Aquifer System ◽  
Flow Equations ◽  
Flow Models ◽  
Future Behavior ◽  
Fence Diagram

 Models are simplification of reality to investigate certain phenomena or to predict future behavior and always tries to generate scenario that is close to the real condition. Groundwater flow models are computer models generated through using established flow equations that simulate and predict aquifer conditions. The result of groundwater modeling is used for groundwater management and remediation. In the present study, hydrostratigraphic units were identified through interpreting the lithological logs of the drilled wells then fence diagram was prepared with three major aquifer horizons, namely unconfined, shallow confined and deep confined aquifers. In addition, hydrogeologic data were integrated to develop a conceptual hydrogeologic model of the aquifer system of the Chitwan Dun valley, which was the basis for the development of the numerical model. The aquifer system was modeled numerically using MODFLOW-2005 numerical modeling, which was further calibrated and an acceptable numerical model was obtained which showed different flow direction in each aquifer layer. The model was validated by comparing the observed and simulated heads. The result shows that in each of the aquifer layers, the general flow direction is towards west and south-west.

Groundwater flow simulation and its application in GaoSong ore field, China

2018 ◽  
Vol 10 (2) ◽  
pp. 276-284 ◽  
Author(s):  
Gang Chen ◽  
Shiguang Xu ◽  
Chunxue Liu ◽  
Lei Lu ◽  
Liang Guo
Keyword(s):  
Numerical Model ◽  
Flow Field ◽  
Groundwater Flow ◽  
Mine Water ◽  
Permeability Coefficient ◽  
Water Inrush ◽  
Seepage Field ◽  
Groundwater Seepage ◽  
Calculation Results ◽  
Groundwater Flow Field

Abstract Mine water inrush is one of the important factors threatening safe production in mines. The accurate understanding of the mine groundwater flow field can effectively reduce the hazards of mine water inrush. Numerical simulation is an important method to study the groundwater flow field. This paper numerically simulates the groundwater seepage field in the GaoSong ore field. In order to ensure the accuracy of the numerical model, the research team completed 3,724 field fissure measurements in the study area. The fracture measurement results were analyzed using the GEOFRAC method and the whole-area fracture network data were generated. On this basis, the rock mass permeability coefficient tensor of the aquifer in the study area was calculated. The tensor calculation results are used in the numerical model of groundwater flow. After calculation, the obtained numerical model can better represent the groundwater seepage field in the study area. In addition, we designed three different numerical models for calculation, mainly to explore the influence of the tensor assignment of permeability coefficient on the calculation results of water yield of the mine. The results showed that irrational fathom tensor assignment would cause a significant deviation in calculation results.

A coupled FE model for the joint resolution of the shallow water and the groundwater flow equations

2014 ◽  
Vol 24 (7) ◽  
pp. 1553-1569 ◽  
Author(s):  
H.G. Rábade ◽  
P. Vellando ◽  
F. Padilla ◽  
R. Juncosa
Keyword(s):  
Groundwater Flow ◽  
Shallow Water ◽  
Free Surface Flow ◽  
Element Model ◽  
Surface Flow ◽  
Fe Model ◽  
Content Type ◽  
Flow Equations ◽  
Natural Watersheds ◽  
Joint Resolution

Purpose – A new coupled finite element model has been developed for the joint resolution of both the shallow water equations, that governs the free surface flow, and the groundwater flow equation that governs the motion of water through a porous media. The paper aims to discuss these issues. Design/methodology/approach – The model is based upon two different modules (surface and ground water) previously developed by the authors, that have been validated separately. Findings – The newly developed software allows for the assessment of the fluid flow in natural watersheds taking into account both the surface and the underground flow in the way it really takes place in nature. Originality/value – The main achievement of this work has dealt with the coupling of both models, allowing for a proper moving interface treatment that simulates the actual interaction that takes place between surface and groundwater in natural watersheds.

Groundwater Flow Equations

2017 ◽  
pp. 15-27
Author(s):  
Florimond De Smedt ◽  
Wouter Zijl
Keyword(s):  
Groundwater Flow ◽  
Flow Equations

Efficient mass conservative numerical model for solving variably saturated groundwater flow

2021 ◽  
Vol 603 ◽  
pp. 126976
Author(s):  
Abdelkrim Aharmouch ◽  
Brahim Amaziane
Keyword(s):  
Numerical Model ◽  
Groundwater Flow

Simulation of Groundwater Flow and Pollutant Transport for Alluvial Aquifer in Kampung Tekek, Tioman Island

2012 ◽  
Author(s):  
Norhan Abd. Rahman ◽  
Woei–Keong Kuan
Keyword(s):  
Groundwater Flow ◽  
Flow Simulation ◽  
Pollutant Transport ◽  
World Health Organisation ◽  
Peninsular Malaysia ◽  
Tourism Industry ◽  
World Health ◽  
Visual Modflow ◽  
Transport Modelling ◽  
Potential Contaminant

Pulau Tioman terletak di pantai timur Semenanjung Malaysia. Akibat pembangunan yang pesat dalam industri pelancongan, permintaan terhadap bekalan air dijangka akan meningkat di pulau ini. Daripada kajian yang telah dijalankan sebelumnya, didapati airbumi merupakan sumber air yang berpotensi. Satu perisian model 3–dimensi (Visual MODFLOW) telah digunakan untuk menghasilkan model aliran airbumi dan pengangkutan bahan pencemar di Kampung Tekek dengan tujuan meramal simpanan airbumi dan penyebaran bahan pencemar, iaitu nitrat, semasa pengepaman. Daripada keputusan simulasi aliran airbumi yang diperolehi, pengepaman akuifer di Kampung Tekek dapat mencapai pada kadar 4000 m3/hari. Kajian model bahan pencemar menunjukkan kepekatan bahan pencemar nitrat yang tercatat di telaga pam didapati agak rendah dan memenuhi piawaian air minuman World Health Organisation (WHO). Kata kunci: Aliran airbumi, bahan pencemar, model numerik, Visual MODFLOW, pulau Tioman Island is situated in the east coast of Peninsular Malaysia. With rapid growth in tourism industry, the demand for water supply is expected to increase in this island. From previous studies, groundwater was found to be a potential source of water. A 3–dimensional numerical modelling software (Visual MODFLOW) is used to simulate the groundwater flow and pollutant transport of the aquifer in Kampung Tekek, for the prediction of available yield of groundwater, and also for studying the migration of potential contaminant source, i.e. nitrate, due to the withdrawal. The groundwater flow simulation results showed that the aquifer is capable of pumping 4000 m3/day. Results of pollutant transport modelling showed that the estimated concentration of nitrate in the pump well is generally low and complies with World Health Organisation (WHO) standard for drinking water. Key words: Groundwater flow, pollutant transport, numerical model, Visual MODFLOW, island

scholarly journals NUMERICAL MODEL OF BREAKWATER WAVE FLOWS

1988 ◽  
Vol 1 (21) ◽  
pp. 149 ◽  
Author(s):  
Alex C. Thompson
Keyword(s):  
Mathematical Model ◽  
Numerical Model ◽  
Reflection Coefficient ◽  
Water Wave ◽  
Wave Equations ◽  
Seepage Flow ◽  
Experimental Results ◽  
Simplified Model ◽  
Flow Equations ◽  
Shallow Water Wave Equations

A mathematical model of flow on a sloping breakwater face is described and results of calculations compared with some experimental results to show how the model can be calibrated. Flow above the surface of the slope is represented by the shallow water wave equations solved by a finite difference method. Flow within the breakwater is calculated by one of two methods. A solution of the linear seepage flow equations, again using finite differences or a simplified model of inflow can be used. Experimental results for runup and reflection coefficient are from tests performed at HRL Wallingford.

An Efficient Numerical Model of Pulsating Combustion and Its Experimental Validation

2009 ◽  
Author(s):  
Luca Casarsa ◽  
Pietro Giannattasio ◽  
Diego Micheli
Keyword(s):  
Numerical Model ◽  
Combustion Chamber ◽  
Second Order ◽  
Operating Conditions ◽  
Gas Dynamics Equations ◽  
Time Step ◽  
Flow Equations ◽  
Tail Pipe ◽  
Flux Difference ◽  
Pulse Jet

A simple and efficient numerical model is presented for the simulation of pulse combustors. It is based on the numerical solution of the quasi-1D unsteady flow equations and on phenomenological sub-models of turbulence and combustion. The gas dynamics equations are solved by using the Flux Difference Splitting (FDS) technique, a finite-volume upwind numerical scheme, and ENO reconstructions to obtain second-order accurate non-oscillatory solutions. The numerical fluxes computed at the cell interfaces are used to transport also the reacting species, their formation energy and the turbulent kinetic energy. The combustion progress in each cell is evaluated explicitly at the end of each time step according to a second-order overall reaction kinetics. In this way, the computations of gas dynamic evolution and heat release are decoupled, which makes the model particularly simple and efficient. A comprehensive set of measurements has been performed on a small Helmholtz type pulse-jet in order to validate the model. Air and fuel consumptions, wall temperatures, pressure cycles in both combustion chamber and tail-pipe, and instantaneous thrust have been recorded in different operating conditions of the device. The comparison between numerical and experimental results turns out to be satisfactory in all the working conditions of the pulse-jet. In particular, accurate predictions are obtained of the device operating frequency and of shape, amplitude and phase of the pressure waves in both combustion chamber and tail-pipe.

scholarly journals Groundwater Flow Modeling in Karst Aquifers: Coupling 3D Matrix and 1D Conduit Flow via Control Volume Isogeometric Analysis—Experimental Verification with a 3D Physical Model

Water ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1787 ◽  
Author(s):  
Luka Malenica ◽  
Hrvoje Gotovac ◽  
Grgo Kamber ◽  
Srdjan Simunovic ◽  
Srikanth Allu ◽  
...  
Keyword(s):  
Free Surface ◽  
Numerical Model ◽  
Groundwater Flow ◽  
Physical Model ◽  
Isogeometric Analysis ◽  
Numerical Solutions ◽  
Control Volume ◽  
Karst Aquifers ◽  
Conduit Flow ◽  
Laboratory Conditions

A novel numerical model for groundwater flow in karst aquifers is presented. A discrete-continuum (hybrid) approach, in which a three-dimensional matrix flow is coupled with a one-dimensional conduit flow, was used. The laminar flow in the karst matrix is described by a variably saturated flow equation to account for important hydrodynamic effects in both the saturated and unsaturated zones. Turbulent conduit flow for both free surface and pressurized flow conditions was captured via the noninertia wave equation, whereas the coupling of two flow domains was established through an exchange term proportional to head differences. The novel numerical approach based on Fup basis functions and control-volume formulation enabled us to obtain smooth and locally conservative numerical solutions. Due to its similarity to the isogeometric analysis concept (IGA), we labeled it as control-volume isogeometric analysis (CV-IGA). Since realistic verification of the karst flow models is an extremely difficult task, the particular contribution of this work is the construction of a specially designed 3D physical model ( dimensions: 5.66 × 2.95 × 2.00 m) in order to verify the developed numerical model under controlled laboratory conditions. Heterogeneous porous material was used to simulate the karst matrix, and perforated pipes were used as karst conduits. The model was able to capture many flow characteristics, such as the interaction between the matrix and conduit, rainfall infiltration through the unsaturated zone, direct recharge through sinkholes, and both free surface and pressurized flow in conduits. Two different flow experiments are presented, and comparison with numerical results confirmed the validity of the developed karst flow model under complex laboratory conditions.

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