Lattice Boltzmann Simulation Of Multi-charge Transprotation In Dielectric Fluids And Heat Transfer Analysis

Electrohydrodynamics(EHD)is a fundamental topic formed by the combination of fluid dynamics,heat transfer and electrodynamics.Dielectric fluid behaves deserve flow patterns and heat transfer features when driven by outer electric field,which deserves in-depth study.Simultaneously,with the development of the microelectromechanical systems,flow control and heat transfer enhancement technologies achieved by Coulomb driving force have received more and more attention.Studies of electro-thermo convection provide solid foundation for the achievement and development of these technologies.Lattice Boltzmann method is a kind of mesoscopic algorithm which is gradually developing.However it has not been widely used in EHD and multiphysics field couping problems.In this paper,LBM is used to study electro-thermo-convection.Two aspects of work have been done.On the one hand,multi-ion eletro-convection under Dissociation/Recombination mechanism has been studied.We summarized the control equation of multi-ion eletro-convection and analyzed the dimensionless parameters.We developed a kind of LBM model dealing with multi-ion eletro-convection.The model id then used to simulate the ion distribution between a pair of parallel flat.The simulation results are verified by the FVM result,proving the accuracy of the LBM model.A electo-convection configuration from experiment has also been simulated.The simulation result of flow pattern and velocity is verified by experiment data.Further,we studied the influence of electo-Rayleigh number and dimensionless dissociation parameter to the flow pattern and mass transfer.Simulation result show that the former parameter has positive correlation with flow velocity but has no relation to the flow pattern,while the latter one influence both velocity and flow pattern.The single-ion eletro-convection under Injection mechanism is also studied,attending to elaborate the difference between these two mechanisms.On the other hand,the electro-thermo-convection under Ion Injection mechanism has been studied.We first simulate electro-convection and thermo-convection individually,comparing the differences between the flow pattern of two kind of convection.Then we simulate the electro-thermo-convection under different strength of electric driven effect.The result shows that with the enhancement of electric driven strength,lots of swirls are produced in the annulus,and the heat transfer near inner electrode is enhanced.Otherwise,the influence of geometry condition to flow and heat transfer is discussed.This study enriches and strengthens the theory of EHD and multiphysics field couping problem and manages to extend the LBM simulation ability in multi-ion electro-convection,deepen the understanding of electo-thermo convection.