Nanoconfined gas kinetic modelling and transport mechanisms
Abstract
The gas kinetic theory explains macroscopic fluid properties based on microscopic molecular interactions, and has wide applications in aerospace technologies, microelectromechanical systems, and industrial processes. The Boltzmann equation only applies to dilute (ideal) gases as it ignores the gas molecule size and molecular interactions other than binary collision. Starting from the Boltzmann equation, the transport mechanisms of dilute, dense, real, and nanoconfined gases are discussed along with their boundary conditions. Compared with other gas kinetic models, the nanoconfined gas kinetic model produces results consistent with those of the molecular dynamics simulations at the microscopic level and recovers the continuum fluid dynamics when the nonequilibrium, real gas, and confinement effects are negligible. Slip dynamics, real gas effects, and transport mechanisms of nanoconfined gases are numerically analysed. Finally, the limitations and possible directions of nanoconfined gas kinetic modelling are briefly discussed.
