Dissipation and coupled fields

The evolution criterion and the variational formulation of the coupled phenomena in the materials with the inner structure are presented. The evolution criterion, as formulated by Glansdorff and Prigogine, allows to find the kinetic potential descrobing a dissipative process. This paper deals with the construction of the kinetic potential for micropolar media embedded in the dielectric fluid and subjected to the coupled field interactions. Generalization deals with the dissipative mechanical, thermal,and electromagnetic processes occurring in the micropolar medium. The formulated criterion is aplied to obtain the equilibrium conditions for micropolar elastic solids, micropolar electromagnetic fluids, and liquid crystals.The variational principle is constructed for micropolar media in external fields of forces on the example of liguid crystals subjected to the influence of thermal and electromagnetic fields. The problem of the dissipative processes produced in liquid crystals by the exernal end internal fields is considered.