The Experts below are selected from a list of 294 Experts worldwide ranked by ideXlab platform

Mohamed Boutayeb - One of the best experts on this subject based on the ideXlab platform.

  • Control of Transient Coupled Radiative-Conductive Heat Transfer Equation
    IFAC Proceedings Volumes, 2020
    Co-Authors: Cédric Delattre, Hugues Rafaralahy, Gaëtan Didier, Gérard Jeandel, Mohamed Boutayeb
    Abstract:

    Control of the combined Heat Transfer process is presently under consideration for better glass manufacture with less defects. Solution of transient combined radiative and Conductive Heat Transfer in a medium requires the solution of radiative Transfer equation, which usually takes hours to converge using latest finite volume codes. Indeed transient combined radiative and Conductive Heat Transfer in a medium is governed by nonlinear partial integro-differential equations. Simple models are necessary for real time control purposes. First this paper present a reduced model. It is obtained by a polynomial approximation for the combined Heat Transfer and a discretization of PDEs by finite difference method. Then a PI controller of the approximate plant is designed. Convergence is confirmed by simulation results.

  • Galerkin method for solving combined radiative and Conductive Heat Transfer
    International Journal of Thermal Sciences, 2016
    Co-Authors: Mohamed Ghattassi, Jean Rodolphe Roche, Fatmir Asllanaj, Mohamed Boutayeb
    Abstract:

    This article deals with a numerical solution for combined radiation and conduction Heat Transfer in a grey absorbing and emitting medium applied to a two-dimensional domain using triangular meshes. The radiative Transfer equation was solved using the high order Discontinuous Galerkin method with an upwind numerical flux. The energy equation was discretized using a high order finite element method. Stability and error analysis were performed for the Discontinuous Galerkin method to solve radiative Transfer equation. A new algorithm to solve the nonlinear radiative-Conductive Heat Transfer systems was introduced and different types of boundary conditions were considered in numerical simulations. The proposed technique's high performance levels in terms of accuracy and stability are discussed in this paper with numerical examples given.

  • galerkin method for solving combined radiative and Conductive Heat Transfer
    International Journal of Thermal Sciences, 2016
    Co-Authors: Jean Rodolphe Roche, Mohamed Ghattassi, Fatmir Asllanaj, Mohamed Boutayeb
    Abstract:

    This article deals with a numerical solution for combined radiation and conduction Heat Transfer in a gray absorbing and emitting medium applied to a two-dimensional domain using triangular meshes. The radiative Transfer equation was solved using the high order Discontinuous Galerkin method with an upwind numerical flux. The energy equation was discretized using a high order finite element method. Stability and error analysis were performed for the Discontinuous Galerkin method to solve radiative Transfer equation. A new algorithm to solve the nonlinear radiative–Conductive Heat Transfer systems was introduced and different types of boundary conditions were considered in numerical simulations. The proposed technique's high performance levels in terms of accuracy and stability are discussed in this paper with numerical examples given.

  • State observer design for non linear coupled partial differential equations with application to radiative-Conductive Heat Transfer systems
    53rd IEEE Conference on Decision and Control, 2014
    Co-Authors: Mohamed Ghattassi, Mohamed Boutayeb, J. R. Roche
    Abstract:

    This contribution deals with state observer design for a class of nonlinear coupled PDE that describe radiative-Conductive Heat Transfer systems. This approach uses first a stable spatial discretization technique that is the Galerkin method to obtain a large scale but finite dimensional system in a suitable form. Thanks to the special structure of the obtained state system, the second main result is to show through the differential mean value theorem (DMVT) that there always exists an observer gain matrix that assures asymptotic convergence. On the other hand, in order to avoid high computational requirements, we show how to construct the observer gain matrix so that the stability condition, written in terms of linear matrix inequality, is satisfied. Extension to H∞ performance analysis is also proposed. In order to show high accuracy of the proposed technique, a numerical example is provided.

Fatmir Asllanaj - One of the best experts on this subject based on the ideXlab platform.

  • CONVERGENCE OF A NUMERICAL SCHEME FOR A NONLINEAR COUPLED SYSTEM OF RADIATIVE-Conductive Heat Transfer EQUATIONS
    Mathematical Models and Methods in Applied Sciences, 2020
    Co-Authors: J. R. Roche, Fatmir Asllanaj, Gérard Jeandel
    Abstract:

    In this paper, we prove the convergence of a numerical scheme for one-dimensional coupled system of nonlinear partial and ordinary integro-differential equations. This system describes the steady-state coupled radiative-Conductive Heat Transfer for a non-grey anisotropically absorbing, emitting and scattering medium, with axial symmetry and nonhomogeneous Dirichlet boundary conditions. The convergence proof follows from monotonicity arguments and the application of a discrete fixed-point problem, involving only to the temperature fields.

  • Galerkin method for solving combined radiative and Conductive Heat Transfer
    International Journal of Thermal Sciences, 2016
    Co-Authors: Mohamed Ghattassi, Jean Rodolphe Roche, Fatmir Asllanaj, Mohamed Boutayeb
    Abstract:

    This article deals with a numerical solution for combined radiation and conduction Heat Transfer in a grey absorbing and emitting medium applied to a two-dimensional domain using triangular meshes. The radiative Transfer equation was solved using the high order Discontinuous Galerkin method with an upwind numerical flux. The energy equation was discretized using a high order finite element method. Stability and error analysis were performed for the Discontinuous Galerkin method to solve radiative Transfer equation. A new algorithm to solve the nonlinear radiative-Conductive Heat Transfer systems was introduced and different types of boundary conditions were considered in numerical simulations. The proposed technique's high performance levels in terms of accuracy and stability are discussed in this paper with numerical examples given.

  • galerkin method for solving combined radiative and Conductive Heat Transfer
    International Journal of Thermal Sciences, 2016
    Co-Authors: Jean Rodolphe Roche, Mohamed Ghattassi, Fatmir Asllanaj, Mohamed Boutayeb
    Abstract:

    This article deals with a numerical solution for combined radiation and conduction Heat Transfer in a gray absorbing and emitting medium applied to a two-dimensional domain using triangular meshes. The radiative Transfer equation was solved using the high order Discontinuous Galerkin method with an upwind numerical flux. The energy equation was discretized using a high order finite element method. Stability and error analysis were performed for the Discontinuous Galerkin method to solve radiative Transfer equation. A new algorithm to solve the nonlinear radiative–Conductive Heat Transfer systems was introduced and different types of boundary conditions were considered in numerical simulations. The proposed technique's high performance levels in terms of accuracy and stability are discussed in this paper with numerical examples given.

  • coupled radiative and Conductive Heat Transfer in a non grey absorbing and emitting semitransparent media under collimated radiation
    Journal of Quantitative Spectroscopy & Radiative Transfer, 2002
    Co-Authors: David Lacroix, Fatmir Asllanaj, Gilles Parent, G Jeandel
    Abstract:

    Abstract This paper deals with Heat Transfer in non-grey semitransparent two-dimensional sample. Considering an homogeneous purely absorbing medium, we calculated the temperature field and Heat fluxes of a material irradiated under a specific direction. Coupled radiative and Conductive Heat Transfer were considered. The radiative Heat Transfer equation (RTE) was solved using a S8 quadrature and a discrete ordinate method. Reflection and absorption coefficients of the medium were calculated with the silica optical properties. The conduction inside the medium was linked to the RTE through the energy conservation. Validation of the model and two original cases are also presented.

  • a finite difference solution of non linear systems of radiative Conductive Heat Transfer equations
    International Journal for Numerical Methods in Engineering, 2002
    Co-Authors: Fatmir Asllanaj, A Milandri, G Jeandel, Jean Rodolphe Roche
    Abstract:

    A finite difference solution for a system of non-linear integro–differential equations modelling the steady-state combined radiative–Conductive Heat Transfer is proposed. A new backward–forward finite difference scheme is formulated for the Radiative Transfer Equation. The non-linear Heat conduction equation is solved using the Kirchhoff transformation associated with a centred finite difference scheme. The coupled system of equations is solved using a fixed-point method, which relates to the temperature field. An application on a real insulator composed of silica fibres is illustrated. The results show that the method is very efficient. Copyright © 2002 John Wiley & Sons, Ltd.

Jean Rodolphe Roche - One of the best experts on this subject based on the ideXlab platform.

  • Galerkin method for solving combined radiative and Conductive Heat Transfer
    International Journal of Thermal Sciences, 2016
    Co-Authors: Mohamed Ghattassi, Jean Rodolphe Roche, Fatmir Asllanaj, Mohamed Boutayeb
    Abstract:

    This article deals with a numerical solution for combined radiation and conduction Heat Transfer in a grey absorbing and emitting medium applied to a two-dimensional domain using triangular meshes. The radiative Transfer equation was solved using the high order Discontinuous Galerkin method with an upwind numerical flux. The energy equation was discretized using a high order finite element method. Stability and error analysis were performed for the Discontinuous Galerkin method to solve radiative Transfer equation. A new algorithm to solve the nonlinear radiative-Conductive Heat Transfer systems was introduced and different types of boundary conditions were considered in numerical simulations. The proposed technique's high performance levels in terms of accuracy and stability are discussed in this paper with numerical examples given.

  • galerkin method for solving combined radiative and Conductive Heat Transfer
    International Journal of Thermal Sciences, 2016
    Co-Authors: Jean Rodolphe Roche, Mohamed Ghattassi, Fatmir Asllanaj, Mohamed Boutayeb
    Abstract:

    This article deals with a numerical solution for combined radiation and conduction Heat Transfer in a gray absorbing and emitting medium applied to a two-dimensional domain using triangular meshes. The radiative Transfer equation was solved using the high order Discontinuous Galerkin method with an upwind numerical flux. The energy equation was discretized using a high order finite element method. Stability and error analysis were performed for the Discontinuous Galerkin method to solve radiative Transfer equation. A new algorithm to solve the nonlinear radiative–Conductive Heat Transfer systems was introduced and different types of boundary conditions were considered in numerical simulations. The proposed technique's high performance levels in terms of accuracy and stability are discussed in this paper with numerical examples given.

  • a finite difference solution of non linear systems of radiative Conductive Heat Transfer equations
    International Journal for Numerical Methods in Engineering, 2002
    Co-Authors: Fatmir Asllanaj, A Milandri, G Jeandel, Jean Rodolphe Roche
    Abstract:

    A finite difference solution for a system of non-linear integro–differential equations modelling the steady-state combined radiative–Conductive Heat Transfer is proposed. A new backward–forward finite difference scheme is formulated for the Radiative Transfer Equation. The non-linear Heat conduction equation is solved using the Kirchhoff transformation associated with a centred finite difference scheme. The coupled system of equations is solved using a fixed-point method, which relates to the temperature field. An application on a real insulator composed of silica fibres is illustrated. The results show that the method is very efficient. Copyright © 2002 John Wiley & Sons, Ltd.

Mohamed Ghattassi - One of the best experts on this subject based on the ideXlab platform.

  • Galerkin method for solving combined radiative and Conductive Heat Transfer
    International Journal of Thermal Sciences, 2016
    Co-Authors: Mohamed Ghattassi, Jean Rodolphe Roche, Fatmir Asllanaj, Mohamed Boutayeb
    Abstract:

    This article deals with a numerical solution for combined radiation and conduction Heat Transfer in a grey absorbing and emitting medium applied to a two-dimensional domain using triangular meshes. The radiative Transfer equation was solved using the high order Discontinuous Galerkin method with an upwind numerical flux. The energy equation was discretized using a high order finite element method. Stability and error analysis were performed for the Discontinuous Galerkin method to solve radiative Transfer equation. A new algorithm to solve the nonlinear radiative-Conductive Heat Transfer systems was introduced and different types of boundary conditions were considered in numerical simulations. The proposed technique's high performance levels in terms of accuracy and stability are discussed in this paper with numerical examples given.

  • galerkin method for solving combined radiative and Conductive Heat Transfer
    International Journal of Thermal Sciences, 2016
    Co-Authors: Jean Rodolphe Roche, Mohamed Ghattassi, Fatmir Asllanaj, Mohamed Boutayeb
    Abstract:

    This article deals with a numerical solution for combined radiation and conduction Heat Transfer in a gray absorbing and emitting medium applied to a two-dimensional domain using triangular meshes. The radiative Transfer equation was solved using the high order Discontinuous Galerkin method with an upwind numerical flux. The energy equation was discretized using a high order finite element method. Stability and error analysis were performed for the Discontinuous Galerkin method to solve radiative Transfer equation. A new algorithm to solve the nonlinear radiative–Conductive Heat Transfer systems was introduced and different types of boundary conditions were considered in numerical simulations. The proposed technique's high performance levels in terms of accuracy and stability are discussed in this paper with numerical examples given.

  • State observer design for non linear coupled partial differential equations with application to radiative-Conductive Heat Transfer systems
    53rd IEEE Conference on Decision and Control, 2014
    Co-Authors: Mohamed Ghattassi, Mohamed Boutayeb, J. R. Roche
    Abstract:

    This contribution deals with state observer design for a class of nonlinear coupled PDE that describe radiative-Conductive Heat Transfer systems. This approach uses first a stable spatial discretization technique that is the Galerkin method to obtain a large scale but finite dimensional system in a suitable form. Thanks to the special structure of the obtained state system, the second main result is to show through the differential mean value theorem (DMVT) that there always exists an observer gain matrix that assures asymptotic convergence. On the other hand, in order to avoid high computational requirements, we show how to construct the observer gain matrix so that the stability condition, written in terms of linear matrix inequality, is satisfied. Extension to H∞ performance analysis is also proposed. In order to show high accuracy of the proposed technique, a numerical example is provided.

Gintautas Miliauskas - One of the best experts on this subject based on the ideXlab platform.

  • regularities of unsteady radiative Conductive Heat Transfer in evaporating semitransparent liquid droplets
    International Journal of Heat and Mass Transfer, 2001
    Co-Authors: Gintautas Miliauskas
    Abstract:

    Abstract The numerical investigation method of unsteady Transfer processes in evaporating droplets in radiating media is introduced, evaluating the dependence of optical spectral properties of material upon temperature. The distribution of temperature and Heat fluxes regularities in Heating and simultaneously evaporating water droplets has been investigated. It is shown that as a cause of interaction of radiation and conduction processes, the profile of the temperature field inside the droplet is distorted, and the magnitude and direction of Heat conductivity flux vector changes. According to the maximum place in the instant temperature field of the droplet, it is suggested to distinguish three periods of state change for an evaporating droplet: initial, transient and final. The results of the unsteady radiative–Conductive Heat Transfer are generalized by using similarity theory methods.