Molecular Dynamics (MD) Simulation of Nanoscale Flow
Objective: In this study, Molecular Dynamics Simulations are performed to simulate the external flow and heat transfer in nano-fins. Also MD simulations will be performed on the fluid flow inside the nanotubes.
Problem Definition: Carbon nanotubes are highly conductive, so they can act as excellent materials as nanofins. MD simulations are performed to study the effect of interfacial resistance on the performance of the CNTs as nanofins. Also, internal flow in nanotubes is of great interest. The significance of such studies is in applications such as cellular probes, drug delivery and nanometer sized pipes in micro/nano-fluidics systems. MD simulations are performed to study the behavior of fluids inside the nanotubes.
General Procedure: Molecular Dynamics simulations are performed on the carbon nanotubes and matrix system. Single walled nanotubes immersed in fluids are used in the analysis. For example, the carbon and hydrogen atoms are modeled explicitly (Figure 1). In the simulations the energy of the entire system is minimized and later equilibrated for 1ps (Figure 2). The temperature scaling is carried out for 10ps using ensemble average. Periodic boundary conditions are applied in all directions. In the molecular dynamic simulations, the inter-atomic interactions are calculated using Universal Force Field.
Conclusion and Future Direction: There is a large interfacial resistance at the carbon nanotubes-matrix interface due to the weak coupling between the rigid tube structure and the soft liquid (Figures 3 and 4). The future study involves finding various methods to decrease the interfacial resistance in nanotubes. Other future studies involve investigating the behavior and mechanical properties of the fluid confined in the nanotubes by performing MD simulation on the confined systems.
V. U. Unnikrishnan, D. Banerjee, and J. N. Reddy, "Atomistic-Mesoscale Interfacial Resistance Based Thermal Analysis of Carbon Nanotube Systems," International Journal of Thermal Sciences, Vol. 47, No. 12, pp. 1602-1609, 2008.