Modeling dissipative processes in open and closed hydrodynamic systems

In this paper, the modeling of transport processes in both closed and open hydrodynamic systems is discussed. The main focus is on reviewing the relevant mechanisms. It is shown that in weakly nonequilibrium systems, dissipative processes are caused by microscopic thermal molecular fluctuations, and their irreversibility is associated with the non-potential nature of intermolecular interactions. In open hydrodynamic systems the rheology of the fluid changes at sufficiently high shear rates. The nature of these changes is demonstrated using molecular dynamics simulations. It is established that with increasing shear rate, both simple liquid and nanofluids become pseudoplastic. In the latter case, the critical shear rate of rheology change depends on the concentration of nanoparticles and their size. However, at sufficiently high shear rates, dissipative processes cease to depend on the sizes of the internal structural elements of the medium. Its viscosity drops sharply. In all cases, the change in the rheology of the medium is associated with the transformation of its structure. In particular, with the degradation of the short-range order.

diffusion, dissipative processes, fluctuation-dissipation theorem, irreversibility, molecular dynamics, nanofluids, rheology, transport equations, transport processes, viscosity, fluctuation-dissipation theorem