Statistical mechanics of transport processes of fluids under confined conditions

Аннотация

The problem of adequately describing transport processes of fluids in confined conditions is solved using methods of nonequilibrium statistical mechanics. The ‘fluid–channel wall’ system is regarded as a two-fluid medium, in which each phase has a particular velocity and temperature. The obtained results show that the transport equations in confined spaces should contain not only the stress tensor and the heat flux vector, but also the interfacial forces responsible for the transfer of momentum and heat due to the interaction with the wall surfaces. The stress tensor and the heat flux vector fluid can be expressed in terms of the effective viscosity and thermal conductivity. However, the constitutive relations contain additive terms that correspond to fluid–surface interactions. Thus, not only do the fluid transport coefficients in nanochannels differ from the bulk transport coefficients, but they are also not only determined by the parameters of the fluid.