Abstract
This thesis mainly employs the Boltzmann Transport Equation (BTE), which is based on the non-continuum particle collision dynamics, to analyze the transport phenomena as below: (1) two-phase boltzon (fluid particle) flow in a micro-channel; (2) electric and thermal conductivities of electron flow in a nanowire; (3) thermal conductivity of phonon flow in micro and nanowires. The Boltzmann Transport Equation has been discretized to transform into a lattice Boltzmann model (LBM) and energy conservation is further considered to derive into a thermal lattice Boltzmann scheme (TLBM). The Boltzmann-Maxwell distribution is assumed for the equilibrium velocity distribution function. This thesis takes a microchannel two-phase flow as an example to verify the scheme for checking the thermal effect on the bubble transportation. The BTE is also employed to analyze an electron flow in a nanowire, assuming the Fermi-Dirac distribution is valid. Since electrons are inherent in particle-wave duality, a computational quantum mechanics (CQM) platform has to be employed to provide the relationship between the density of state versus energy level. A 1nm diameter Si-Ge superlattice nanowire has been taken as an example to calculate the electron conductivity, electron thermal conductivity, as well as the Seebeck coefficient. Since the same computational quantum technique is too time-consuming to calculate the phonon flow in the nanowires, a modified phonon Boltzann scheme, using discrete ordinate method (DOM), has been derived. The phonon intensity is used to replace the velocity function and the Bose-Einstein distribution was assumed. The new scheme is able to perform more efficient computation and reasonable accuracy on thermal conductivity evaluation in both nano-scale nanowires and micro-scale microwires.