MOLECULAR DYNAMICS SIMULATIONS OF HEAT TRANSFER IN NANOSCALE LIQUID FILMS A Dissertation by

Molecular Dynamics Simulations of Heat Transfer in Nanoscale Liquid Films. (May 2009) Bo Hung Kim, B.A., Yonsei University; M.S., Texas A&M University Co-Chairs of Advisory Committee: Dr. Ali Beskok Dr. Tahir Cagin Molecular Dynamics (MD) simulations of nano-scale flows typically utilize fixed lattice crystal interactions between the fluid and stationary wall molecules. This approach cannot properly model thermal interactions at the wall-fluid interface. In order to properly simulate the flow and heat transfer in nano-scale channels, an interactive thermal wall model is developed. Using this model, the Fourier’s law of heat conduction is verified in a 3.24 nm height channel, where linear temperature profiles with constant thermal conductivity is obtained. The thermal conductivity is verified using the predictions of Green-Kubo theory. MD simulations at different wall wettability (εωf/ε ) and crystal bonding stiffness values (K) have shown temperature jumps at the liquid/solid interface, corresponding to the well known Kapitza resistance. Using systematic studies, the thermal resistance length at the interface is characterized as a function of the surface wettability, thermal oscillation frequency, wall temperature and thermal gradient. An empirical model for the thermal resistance length, which could be used as the jump-coefficient of a Navier boundary condition, is developed. Temperature