Influence of the dispersion on some structures in solids and fluids

摘要

Any movement of an elementary volume of liquid at the moment can be considered as a result of the following motion: quasi-solid motion that is translation with selecting pole, rotating motion around this pole and deformation motion. This theorem was proved by Helmholtz. Prandtl formulated the concept of hardplastic body as the theory of ideal plasticity. Usually we do not take into account twist velocity. The angular momentum is responsible for the twist velocity. In [3] a relation between the conservation laws in continual mechanics and variation of the angular momentum in an elementary volume was considered. The laws was obtained from the modified Boltzmann equation for gas but the reasons of modification were not enough discussed. We begin this paper with some notation about singularity of the Boltzmann equation. It can be deduced both from the equation for N-particle distribution function and as a balance of particles of analyzed value in an elementary volume.