Equilibrium State And Its Stability Of Dielectric System Acted By Electrostatic Fields

The research content of thermodynamics is the interaction of energy between different systems,or system between the outside world.Whether system has heat transfer or works on the external environment,the essence of the process is the transfer of energy.The universality and unity of energy transfer in nature is the basis of the universality of thermodynamics.Thermodynamics is use the defining of the system's state and state functions to describe changes in system energy.So the focus of classical thermodynamics is to study the system state(especially the equilibrium state).Thermodynamic equilibrium state has the lowest possible energy,any non-equilibrium state is approaching equilibrium state unless existing external interactions,and unified state parameters can be assigned only to the equilibrium state.Electromagnetic fields can effectively enhance the heat and mass transfer processes,and it also has obvious effects on the equilibrium and stability of dielectric system.Based on the first and second laws of thermodynamics,the electric field energy is introduced into the thermodynamic differential equation,from which a new entropy function of dielectric system with the influence of electric field is deduced.Then,the equilibrium conditions and the stable conditions of dielectric systems under the action of electrostatic fields are derived from the entropy criterion.The new equilibrium conditions require that the temperature,effective pressure,effective chemical potential,and electric field are uniform through the whole system.The new stable conditions require that the electric charges on the metal plates are proportional to the electric potential.This effective pressure includes mechanical effect from polarization,and the mechanical equilibrium is determined by real pressure and the electric polarization force.The effective chemical potential includes the effect of polarization potential energy,and the phase equilibrium is determined by concentration and polarization potential energy.Using the effective thermodynamic parameters,the thermodynamic properties of the dielectric system under the action of electrostatic field can be accurately described.All the thermodynamic conclusions derived in this paper have experimental literature support.