The Experts below are selected from a list of 303 Experts worldwide ranked by ideXlab platform

Sébastien Imperiale - One of the best experts on this subject based on the ideXlab platform.

  • Construction and analysis of fourth order, energy consistent, family of explicit time discretizations for dissipative Linear Wave equations
    ESAIM: Mathematical Modelling and Numerical Analysis, 2019
    Co-Authors: Juliette Chabassier, Julien Diaz, Sébastien Imperiale
    Abstract:

    This paper deals with the construction of a family of fourth order, energy consistent, explicit time discretizations for dissipative Linear Wave equations. The schemes are obtained by replacing the inversion of a matrix, that comes naturally after using the technique of the Modified Equation on the second order Leap Frog scheme applied to dissipative Linear Wave equations, by explicit approximations of its inverse. The stability of the schemes are studied using an energy analysis and a convergence analysis is carried out. Numerical results in 1D illustrate the space/time convergence properties of the schemes and their efficiency is compared to more classical time discretizations.

  • space time convergence analysis of a class of conservative schemes for Linear Wave equations
    Comptes Rendus Mathematique, 2017
    Co-Authors: Juliette Chabassier, Sébastien Imperiale
    Abstract:

    Abstract This paper concerns the space/time convergence analysis of conservative two-step time discretizations for Linear Wave equations. Explicit and implicit, second- and fourth-order schemes are considered, while the space discretization is given and satisfies minimal hypotheses. Convergence analysis is done using energy techniques and holds if the time step is upper-bounded by a quantity depending on space discretization parameters. In addition to showing the convergence for recently introduced fourth-order schemes, the novelty of this work consists in the independency of the convergence estimates with respect to the difference between the time step and its greatest admissible value.

  • Space/Time convergence analysis of a class of conservative schemes for Linear Wave equations
    Comptes Rendus Mathématique, 2017
    Co-Authors: Juliette Chabassier, Sébastien Imperiale
    Abstract:

    This paper concerns the space/time convergence analysis of conservative two-steps time discretizations for Linear Wave equations. Explicit and implicit, second and fourth order schemes are considered, while the space discretization is given and satisfies minimal hypotheses. The convergence analysis is done using energy techniques and holds if the time step is upper-bounded by a quantity depending on space discretization parameters. In addition to showing the convergence for recently introduced fourth order schemes, the novelty of this work consists in the independency of the convergence estimates with respect to the difference between the time step and its greatest admissible value.

  • Fourth-order energy-preserving locally implicit time discretization for Linear Wave equations
    2015
    Co-Authors: Juliette Chabassier, Sébastien Imperiale
    Abstract:

    A family of fourth order locally implicit schemes is presented as a special case of fourth order coupled implicit schemes for Linear Wave equations. The domain of interest is decomposed into several regions where different (explicit or implicit) fourth order time discretization are used. The coupling is based on a Lagrangian formulation on the boundaries between the several non conforming meshes of the regions. Fourth order accuracy follows from global energy identities. Numerical results in 1d and 2d illustrate the good behavior of the schemes and their potential for the simulation of realistic highly heterogeneous media or strongly refined geometries, for which using everywhere an explicit scheme can be extremely penalizing. Fourth order accuracy reduces the numerical dispersion inherent to implicit methods used with a large time step, and makes this family of schemes attractive compared to classical approaches.

Juliette Chabassier - One of the best experts on this subject based on the ideXlab platform.

  • Construction and analysis of fourth order, energy consistent, family of explicit time discretizations for dissipative Linear Wave equations
    ESAIM: Mathematical Modelling and Numerical Analysis, 2019
    Co-Authors: Juliette Chabassier, Julien Diaz, Sébastien Imperiale
    Abstract:

    This paper deals with the construction of a family of fourth order, energy consistent, explicit time discretizations for dissipative Linear Wave equations. The schemes are obtained by replacing the inversion of a matrix, that comes naturally after using the technique of the Modified Equation on the second order Leap Frog scheme applied to dissipative Linear Wave equations, by explicit approximations of its inverse. The stability of the schemes are studied using an energy analysis and a convergence analysis is carried out. Numerical results in 1D illustrate the space/time convergence properties of the schemes and their efficiency is compared to more classical time discretizations.

  • space time convergence analysis of a class of conservative schemes for Linear Wave equations
    Comptes Rendus Mathematique, 2017
    Co-Authors: Juliette Chabassier, Sébastien Imperiale
    Abstract:

    Abstract This paper concerns the space/time convergence analysis of conservative two-step time discretizations for Linear Wave equations. Explicit and implicit, second- and fourth-order schemes are considered, while the space discretization is given and satisfies minimal hypotheses. Convergence analysis is done using energy techniques and holds if the time step is upper-bounded by a quantity depending on space discretization parameters. In addition to showing the convergence for recently introduced fourth-order schemes, the novelty of this work consists in the independency of the convergence estimates with respect to the difference between the time step and its greatest admissible value.

  • Space/Time convergence analysis of a class of conservative schemes for Linear Wave equations
    Comptes Rendus Mathématique, 2017
    Co-Authors: Juliette Chabassier, Sébastien Imperiale
    Abstract:

    This paper concerns the space/time convergence analysis of conservative two-steps time discretizations for Linear Wave equations. Explicit and implicit, second and fourth order schemes are considered, while the space discretization is given and satisfies minimal hypotheses. The convergence analysis is done using energy techniques and holds if the time step is upper-bounded by a quantity depending on space discretization parameters. In addition to showing the convergence for recently introduced fourth order schemes, the novelty of this work consists in the independency of the convergence estimates with respect to the difference between the time step and its greatest admissible value.

  • Fourth-order energy-preserving locally implicit time discretization for Linear Wave equations
    2015
    Co-Authors: Juliette Chabassier, Sébastien Imperiale
    Abstract:

    A family of fourth order locally implicit schemes is presented as a special case of fourth order coupled implicit schemes for Linear Wave equations. The domain of interest is decomposed into several regions where different (explicit or implicit) fourth order time discretization are used. The coupling is based on a Lagrangian formulation on the boundaries between the several non conforming meshes of the regions. Fourth order accuracy follows from global energy identities. Numerical results in 1d and 2d illustrate the good behavior of the schemes and their potential for the simulation of realistic highly heterogeneous media or strongly refined geometries, for which using everywhere an explicit scheme can be extremely penalizing. Fourth order accuracy reduces the numerical dispersion inherent to implicit methods used with a large time step, and makes this family of schemes attractive compared to classical approaches.

Weijia Yuan - One of the best experts on this subject based on the ideXlab platform.

  • Designing and testing composite energy storage systems for regulating the outputs of Linear Wave energy converters
    Energies, 2017
    Co-Authors: Zanxiang Nie, Xi Xiao, Pritesh Hiralal, Xuanrui Huang, Richard A. Mcmahon, Min Zhang, Weijia Yuan
    Abstract:

    Linear Wave energy converters generate intrinsically intermittent power with variable frequency and amplitude. A composite energy storage system consisting of batteries and super capacitors has been developed and controlled by buck-boost converters. The purpose of the composite energy storage system is to handle the fluctuations and intermittent characteristics of the renewable source, and hence provide a steady output power. Linear Wave energy converters working in conjunction with a system composed of various energy storage devices, is considered as a microsystem, which can function in a stand-alone or a grid connected mode. Simulation results have shown that by applying a boost H-bridge and a composite energy storage system more power could be extracted from Linear Wave energy converters. Simulation results have shown that the super capacitors charge and discharge often to handle the frequent power fluctuations, and the batteries charge and discharge slowly for handling the intermittent power of Wave energy converters. Hardware systems have been constructed to control the Linear Wave energy converter and the composite energy storage system. The performance of the composite energy storage system has been verified in experiments by using electronics-based Wave energy emulators.

  • SMES-Battery energy storage system for conditioning outputs from direct drive Linear Wave energy converters
    IEEE Transactions on Applied Superconductivity, 2013
    Co-Authors: Zanxiang Nie, X.a Xiao, Qing Kang, Huiming Zhang, Raj Aggarwal, Weijia Yuan
    Abstract:

    The power from direct drive Linear Wave energy converter (DDLWEC) consists of frequent power fluctuations and long-term power fluctuations due to oceanic conditions. A 60 kJ superconducting magnetic energy storage is designed to work in conjunction with batteries as a hybrid energy storage system for conditioning the outputs from DDLWECs. The issues of the intrinsic power fluctuations of DDLWECs and the intermittent power generation are both addressed by the hybrid energy storage system.

Min Xiao - One of the best experts on this subject based on the ideXlab platform.

  • particlelike behavior of topological defects in Linear Wave packets in photonic graphene
    Physical Review Letters, 2019
    Co-Authors: Zhaoyang Zhang, Guillaume Malpuech, Changbiao Li, S. V. Koniakhin, Feng Li, Yiqi Zhang, Yanpeng Zhang, O Bleu, Min Xiao
    Abstract:

    : Topological defects, such as quantum vortices, determine the properties of quantum fluids. Their study has been at the center of activity in solid state and BEC communities. In parallel, the nontrivial behavior of Linear Wave packets with complex phase patterns was investigated by singular optics. Here, we study the formation, evolution, and interaction of optical vortices in Wave packets at the Dirac point in photonic graphene. We show that while their exact behavior goes beyond the Dirac equation and requires a full account of the lattice properties, it can be still approximately described by an effective theory considering the phase singularities as "particles". These particles are capable of mutual interaction, with their trajectory obeying the laws of dynamics.

  • particlelike behavior of topological defects in Linear Wave packets in photonic graphene
    Physical Review Letters, 2019
    Co-Authors: Zhaoyang Zhang, Guillaume Malpuech, Changbiao Li, S. V. Koniakhin, Feng Li, Yiqi Zhang, Yanpeng Zhang, O Bleu, Min Xiao
    Abstract:

    : Topological defects, such as quantum vortices, determine the properties of quantum fluids. Their study has been at the center of activity in solid state and BEC communities. In parallel, the nontrivial behavior of Linear Wave packets with complex phase patterns was investigated by singular optics. Here, we study the formation, evolution, and interaction of optical vortices in Wave packets at the Dirac point in photonic graphene. We show that while their exact behavior goes beyond the Dirac equation and requires a full account of the lattice properties, it can be still approximately described by an effective theory considering the phase singularities as "particles". These particles are capable of mutual interaction, with their trajectory obeying the laws of dynamics.

Zanxiang Nie - One of the best experts on this subject based on the ideXlab platform.

  • Designing and testing composite energy storage systems for regulating the outputs of Linear Wave energy converters
    Energies, 2017
    Co-Authors: Zanxiang Nie, Xi Xiao, Pritesh Hiralal, Xuanrui Huang, Richard A. Mcmahon, Min Zhang, Weijia Yuan
    Abstract:

    Linear Wave energy converters generate intrinsically intermittent power with variable frequency and amplitude. A composite energy storage system consisting of batteries and super capacitors has been developed and controlled by buck-boost converters. The purpose of the composite energy storage system is to handle the fluctuations and intermittent characteristics of the renewable source, and hence provide a steady output power. Linear Wave energy converters working in conjunction with a system composed of various energy storage devices, is considered as a microsystem, which can function in a stand-alone or a grid connected mode. Simulation results have shown that by applying a boost H-bridge and a composite energy storage system more power could be extracted from Linear Wave energy converters. Simulation results have shown that the super capacitors charge and discharge often to handle the frequent power fluctuations, and the batteries charge and discharge slowly for handling the intermittent power of Wave energy converters. Hardware systems have been constructed to control the Linear Wave energy converter and the composite energy storage system. The performance of the composite energy storage system has been verified in experiments by using electronics-based Wave energy emulators.

  • SMES-Battery energy storage system for conditioning outputs from direct drive Linear Wave energy converters
    IEEE Transactions on Applied Superconductivity, 2013
    Co-Authors: Zanxiang Nie, X.a Xiao, Qing Kang, Huiming Zhang, Raj Aggarwal, Weijia Yuan
    Abstract:

    The power from direct drive Linear Wave energy converter (DDLWEC) consists of frequent power fluctuations and long-term power fluctuations due to oceanic conditions. A 60 kJ superconducting magnetic energy storage is designed to work in conjunction with batteries as a hybrid energy storage system for conditioning the outputs from DDLWECs. The issues of the intrinsic power fluctuations of DDLWECs and the intermittent power generation are both addressed by the hybrid energy storage system.