Equation of mass balance and equation of particles balance

Two independent functions of state are introduced: density of particles and mass density (2002) [1 - 3]. Such division is important, for example, when the material tends to a fragmentation, as in this case the weight is preserved, but the number of particles changes. Permeability of bodies is determined by the density of particles, and internal interactions are connected with the mass density. Introduction of the function of distribution of particles, in essence, removes the border between discrete and continuous media. Two independent equations are formulated: the equation of mass balance and the equation of balance of particles. A function determining the speed of new particles creation appears in the equation of particles balance; this function in its physical sense can be identified with the chemical potential. The equation of energy balance also contains terms which describe formation of new particles or fragmentation of original particles.
  1. Zhilin P.A. Phase Transitions and General Theory of Elasto-Plastic Bodies // Proceedings of XXIX Summer School - Conference “Advanced Problems in Mechanics”. St. Petersburg, Russia. 2002. P. 36-48.
  2. Zhilin P.A. Mathematical theory of non-elastic media // Uspehi mechaniki (Advances in mechanics). Vol. 2. N 4. 2003. P. 3-36. (In Russian.)
  3. Zhilin P.A. On the general theory of non-elastic media // Mechanics of materials and strength of constructions. Proc. of St. Petersburg State Polytechnical University. N 489. 2004. P. 8-27. (In Russian.)