The Experts below are selected from a list of 16287 Experts worldwide ranked by ideXlab platform

Alfonso M Ganancalvo - One of the best experts on this subject based on the ideXlab platform.

Purbarun Dhar - One of the best experts on this subject based on the ideXlab platform.

  • interplay of electro thermo solutal advection and internal Electrohydrodynamics governed enhanced evaporation of droplets
    Proceedings of The Royal Society A: Mathematical Physical and Engineering Sciences, 2019
    Co-Authors: Vivek Jaiswal, Purbarun Dhar
    Abstract:

    The article experimentally examines and theoretically establishes the influence of electric field on the evaporation kinetics of pendant droplets. It is observed that the evaporation of saline-pendant droplets can be augmented by the application of an external alternating electric field. The evaporation behaviour is modulated by an increase in the field strength and frequency. The classical diffusion driven evaporation model is found insufficient in predicting the improved evaporation rates. The change in surface tension due to field constraint is also unable to explain the observed physics. Consequently, the internal hydrodynamics of the droplet is investigated through particle image velocimetry. The electric field is found to induce enhanced internal advection, which improves the evaporation rates. A scaled analytical model is proposed to quantify the role of internal Electrohydrodynamics, electro-thermal and electro-solutal effects. Stability maps reveal that the advection is caused nearly equally by the electro-solutal and electro-thermal effects within the droplet. The model is able to illustrate the influence played by the governing thermal and solutal Marangoni number, the electro-Prandtl and electro-Schmidt number, and the associated electrohydrodynamic number. The magnitude of the internal circulation can be predicted by the proposed model, which validates the proposed mechanism.

Jun Zhou - One of the best experts on this subject based on the ideXlab platform.

  • an Electrohydrodynamics model for non equilibrium electron and phonon transport in metal films after ultra short pulse laser heating
    European Physical Journal B, 2015
    Co-Authors: Jun Zhou, Ronggui Yang
    Abstract:

    The electrons and phonons in metal films after ultra-short pulse laser heating are in highly non-equilibrium states not only between the electrons and the phonons but also within the electrons. An Electrohydrodynamics model consisting of the balance equations of electron density, energy density of electrons, and energy density of phonons is derived from the coupled non-equilibrium electron and phonon Boltzmann transport equations to study the nonlinear thermal transport by considering the electron density fluctuation and the transient electric current in metal films, after ultra-short pulse laser heating. The temperature evolution is calculated by the coupled electron and phonon Boltzmann transport equations, the Electrohydrodynamics model derived in this work, and the two-temperature model. Different laser pulse durations, film thicknesses, and laser fluences are considered. We find that the two-temperature model overestimates the electron temperature at the front surface of the film and underestimates the damage threshold when the nonlinear thermal transport of electrons is important. The Electrohydrodynamics model proposed in this work could be a more accurate prediction tool to study the non-equilibrium electron and phonon transport process than the two-temperature model and it is much easier to be solved than the Boltzmann transport equations.

  • an Electrohydrodynamics model for non equilibrium electron and phonon transport in metal films after ultra short pulse laser heating
    arXiv: Materials Science, 2014
    Co-Authors: Jun Zhou, Ronggui Yang
    Abstract:

    The electrons and phonons in metal films after ultra-short pulse laser heating are in highly non-equilibrium states not only between the electron sub-system and the phonon sub-system but also within the electron sub-system. An Electrohydrodynamics model consisting of the balance equations of electron density, energy density of electrons, and energy density of phonons is derived from the coupled non-equilibrium electron and phonon Boltzmann transport equations to study the nonlinear transport phenomena, such as the electron density fluctuation and the transient electrical current in metal films, after ultra-short pulse laser heating. The time-dependent temperature distributions is calculated by the coupled electron and phonon Boltzmann transport equations, the Electrohydrodynamics model derived in this work, and the two-temperature model for different laser pulse durations, film thicknesses, and laser fluences. We find that the two-temperature model overestimates the electron temperature at the frontsurface of the film and underestimates the damage threshold when the nonlinear thermal transport of electrons is important. The Electrohydrodynamics model proposedin this work could be a more accurate prediction tool to study the non-equilibrium electron phonon transport process than the two-temperature model and it is much easier to be solved than the coupled electron and phonon Boltzmann transport equations.

Ronggui Yang - One of the best experts on this subject based on the ideXlab platform.

  • an Electrohydrodynamics model for non equilibrium electron and phonon transport in metal films after ultra short pulse laser heating
    European Physical Journal B, 2015
    Co-Authors: Jun Zhou, Ronggui Yang
    Abstract:

    The electrons and phonons in metal films after ultra-short pulse laser heating are in highly non-equilibrium states not only between the electrons and the phonons but also within the electrons. An Electrohydrodynamics model consisting of the balance equations of electron density, energy density of electrons, and energy density of phonons is derived from the coupled non-equilibrium electron and phonon Boltzmann transport equations to study the nonlinear thermal transport by considering the electron density fluctuation and the transient electric current in metal films, after ultra-short pulse laser heating. The temperature evolution is calculated by the coupled electron and phonon Boltzmann transport equations, the Electrohydrodynamics model derived in this work, and the two-temperature model. Different laser pulse durations, film thicknesses, and laser fluences are considered. We find that the two-temperature model overestimates the electron temperature at the front surface of the film and underestimates the damage threshold when the nonlinear thermal transport of electrons is important. The Electrohydrodynamics model proposed in this work could be a more accurate prediction tool to study the non-equilibrium electron and phonon transport process than the two-temperature model and it is much easier to be solved than the Boltzmann transport equations.

  • an Electrohydrodynamics model for non equilibrium electron and phonon transport in metal films after ultra short pulse laser heating
    arXiv: Materials Science, 2014
    Co-Authors: Jun Zhou, Ronggui Yang
    Abstract:

    The electrons and phonons in metal films after ultra-short pulse laser heating are in highly non-equilibrium states not only between the electron sub-system and the phonon sub-system but also within the electron sub-system. An Electrohydrodynamics model consisting of the balance equations of electron density, energy density of electrons, and energy density of phonons is derived from the coupled non-equilibrium electron and phonon Boltzmann transport equations to study the nonlinear transport phenomena, such as the electron density fluctuation and the transient electrical current in metal films, after ultra-short pulse laser heating. The time-dependent temperature distributions is calculated by the coupled electron and phonon Boltzmann transport equations, the Electrohydrodynamics model derived in this work, and the two-temperature model for different laser pulse durations, film thicknesses, and laser fluences. We find that the two-temperature model overestimates the electron temperature at the frontsurface of the film and underestimates the damage threshold when the nonlinear thermal transport of electrons is important. The Electrohydrodynamics model proposedin this work could be a more accurate prediction tool to study the non-equilibrium electron phonon transport process than the two-temperature model and it is much easier to be solved than the coupled electron and phonon Boltzmann transport equations.

Vivek Jaiswal - One of the best experts on this subject based on the ideXlab platform.

  • interplay of electro thermo solutal advection and internal Electrohydrodynamics governed enhanced evaporation of droplets
    Proceedings of The Royal Society A: Mathematical Physical and Engineering Sciences, 2019
    Co-Authors: Vivek Jaiswal, Purbarun Dhar
    Abstract:

    The article experimentally examines and theoretically establishes the influence of electric field on the evaporation kinetics of pendant droplets. It is observed that the evaporation of saline-pendant droplets can be augmented by the application of an external alternating electric field. The evaporation behaviour is modulated by an increase in the field strength and frequency. The classical diffusion driven evaporation model is found insufficient in predicting the improved evaporation rates. The change in surface tension due to field constraint is also unable to explain the observed physics. Consequently, the internal hydrodynamics of the droplet is investigated through particle image velocimetry. The electric field is found to induce enhanced internal advection, which improves the evaporation rates. A scaled analytical model is proposed to quantify the role of internal Electrohydrodynamics, electro-thermal and electro-solutal effects. Stability maps reveal that the advection is caused nearly equally by the electro-solutal and electro-thermal effects within the droplet. The model is able to illustrate the influence played by the governing thermal and solutal Marangoni number, the electro-Prandtl and electro-Schmidt number, and the associated electrohydrodynamic number. The magnitude of the internal circulation can be predicted by the proposed model, which validates the proposed mechanism.