numerical modeling Articles

  • Numerical modeling of geomembranes

    SoilVision Systems Ltd. is pleased to announce the addition of internal boundary conditions which can be used to represent geomembrane materials. The new feature was implemented in response to requests from customers and represents a significant improvement for the numerical modeling of a number of different scenarios involving geomembranes. More specifically, the geomembrane internal boundary ...


    By SoilVision Systems Ltd.

  • Five principles of uncertainty for modelers discussed in November-December issue of Groundwater

    If you’re a member of the NGWA Scientists and Engineers Section, you will soon receive your copy of the November-December 2017 of Groundwater®, an issue brimming with a wide range of topics. In his Guest Editorial, Randall J. Hunt offers five principles of uncertainty for groundwater modelers. He argues that uncertainty must ...

  • Numerical Modeling of a Thermal Conductivity Matric Suction Sensor

    Thermal conductivity matric suction sensors appear to be a promising device for the measurement of suction in soil. The technique indirectly measures matric suction by measuring the thermal conductivity of a ceramic block. This paper uses both a spherical and a cylindrical porous medium to simulate the heat flow in a thermal conductivity matric suction sensor. It is found that, although the ...


    By ASTM International

  • Numerical modelling of air-water flows in sewer drops

    The presence of dissolved oxygen (DO) in water flows is an important factor to ensure the aerobic conditions recognised as beneficial to preventing the occurrence of detrimental effects. The incorporation of DO in wastewater flowing in sewer systems is a process widely investigated in order to quantify the effect of continuous reaeration through the air-liquid interface or air entrained due to ...


    By IWA Publishing

  • The problem of judgement in constructing numerical models for policy analysis

    In many different fields it is now commonplace for complex numerical models to be constructed with a view to illuminating public policy issues. The analysts who construct these models have to make many decisions on how to represent the issues numerically, and they sometimes seek expert advice in this task. In this paper we first justify our assertion that modelling problems of this nature involve ...


    By Inderscience Publishers

  • Two-dimensional numerical modeling of wood transport

    The transport of wood material in rivers has been the subject of various studies in recent years. Most research has focused on the ecological and geomorphologic role of wood, its recruitment processes and spatial distribution in streams. In this study, we focused on wood transport dynamics, and we have developed a numerical model to simulate wood transport coupled with a two-dimensional (2D) ...


    By IWA Publishing

  • Numerical modelling: a tool for better constructed wetland design?

    There is a need for a simplified computer-based design tool for subsurface flow constructed wetlands (CWs) which is based on process-based numerical models. Parameters of existing design guidelines and rules have been derived from experiments under specific conditions. Therefore designing CWs using these parameters is limited to these conditions (i.e. temperature, wastewater composition, filter ...


    By IWA Publishing

  • Numerical model of urban aerodynamics and pollution dispersion

    For analysis of atmospheric processes in the urban environment, the microscale meteorological and dispersion model M2UE is suggested, which takes into account a complex character of aerodynamics in non-uniform urban relief. The three-dimensional version of the model includes a system of Reynolds equations, two-equation k-ε model of turbulence and the 'advection-diffusion' equation to simulate ...


    By Inderscience Publishers

  • On the formulation of environmental fugacity models and their numerical solutions

    Multimedia models based on chemical fugacity, solved numerically, play an important role in investigating and quantifying the environmental fate of chemicals such as persistent organic pollutants (POPs). These models have been utilised extensively in the study of the local and global distribution of chemicals in the environment. This paper describes potential sources of error that may arise ...


    By John Wiley & Sons, Ltd.

  • Numerical prediction of damping in structures with frictional joints

    In many vehicle and space structures, friction in bolted joints is the primary source of energy dissipation during vibrations. Several simplified finite element models have proven their capacity to describe the energy dissipation owing to micro-slip in joints. However, these simplified models require extensive physical testing in order to extract model parameters. This paper proposes a ...


    By Inderscience Publishers

  • Numerical investigation of sodium droplet ignition in the atmospheric air

    The ignition behaviour of sodium droplets in the atmospheric air has been studied numerically with two available models of pre–ignition stage combustion. Surface reaction is very important in the pre–ignition stage, and the different reaction rate–controlling processes involved in this stage are explained using the shrinking core model. The droplet ignition behaviour is studied by considering the ...


    By Inderscience Publishers

  • Numerical simulations of street canyon ventilation and pollutant dispersion

    The relationship among air exchange rate (ACH), pollutant exchange rate (PCH) and friction factor ( f ) is proposed in this study to evaluate the performance of ventilation and pollution removal of hypothetical urban areas. Urban areas were simplified to arrays of idealised, repeated two-dimensional (2D) street canyons of different building-height-to-street-width (aspect) ratios (ARs) and ...


    By Inderscience Publishers

  • Numerical Simulations on Aerodynamics of Thermally Induced Plumes

    Since the physics of air entrainment is not yet clearly understood, most of the fire plume expressions reported in the literature were derived empirically. Experiments with different fire geometry, fuels, and ambient conditions would be difficult when trying to derive comprehensive plume temperature and velocity fields from existing theories. Computational fluid dynamics (CFD), a practical ...


    By SAGE Publications

  • A numerical model of an Active Magnetic Regenerator for refrigeration at room temperature

    In this paper, a numerical model of an Active Magnetic Regenerator (AMR) for refrigeration at room temperature has been evaluated. The model is based on the equation of state of a homogeneous ferromagnetic with reference to the gadolinium used as magnetocaloric substance. In this way the curves of the magnetisation and of the specific heat at constant magnetic field and of the adiabatic ...


    By Inderscience Publishers

  • Meteorological data from numerical weather prediction or observations for dispersion modelling

    Synoptic observations of wind speed, direction, cloud cover, precipitation and temperature are inputs to regulatory dispersion modelling. Numerical Weather Prediction (NWP) data generated by national meteorological services are easily formatted for dispersion models. Changing from observations to NWP data raises concerns amongst regulators and model users – how might impact assessments differ if ...


    By Inderscience Publishers

  • A method of evaluating the topographical effect on atmospheric dispersion using a numerical model

    A method of evaluating topographical effects on exhaust gas dispersion using a numerical model is proposed. The numerical model consists of a turbulence closure model and a Lagrangian particle dispersion model. The topographical effect was evaluated in terms of the ratios of maximum concentration and the distance of the point of maximum concentration from the source on the topography to the ...


    By Inderscience Publishers

  • Numerical study of some high PM10 level episodes

    The study examines the ability of US EPA Models-3 system to reproduce air pollution episodes and to evaluate the role of different processes in the PM10 pattern formation. The case study focuses on three major PM10 episodes, that occurred over Germany in February and March of 2003. The emission input is prepared on the basis of the TNO inventory. The simulated PM10 concentrations are compared ...


    By Inderscience Publishers

  • Numerical Simulation of Spray Pattern in a Liquid Flashing Column

    Spray columns and towers are fundamental in many industrial applications. Understanding the spray pattern in these dynamic environments is very important in the design of an overall spray system solution. Traditional laboratory physical experiments can be time-consuming, expensive, and sometimes impossible to complete. Computational fluid dynamics (CFD) modeling can be used effectively in this ...


    By Spraying Systems Co.

  • Geometric issues in reverse osmosis: numerical simulation and experimentation

    This investigation is a synergistic combination of laboratory experimentation and numerical simulation to quantify the practical impact of geometric imperfections in the flow channels of a reverse osmosis (RO) system. To this end, carefully executed experiments are performed to quantify the fluid flow in a system containing feed spacers which are embedded in the RO membrane. In a complementary ...


    By IWA Publishing

  • An improved numerical scheme for the approximate solution of the Parabolic Wave model

    In this paper, the main features and performances of a new numerical scheme, ILILPM (Improved Locally and Instantaneously Linearized Parabolic Model) are described. ILILPM is an improved version of the Parabolic and Backwater (PAB) and Linearized Parabolic Model (LPM) schemes, proposed in literature for the approximate solution of the Parabolic Wave model. The algorithm presented is able to take ...


    By IWA Publishing

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