EFFECT OF POLYMER CHAINS ON HEAT TRANSFER ON NANOFINS Conference Paper uri icon

abstract

  • Recent experimental results show that precipitation of nanoparticles on heater surfaces can result in heat flux enhancements observed in nanofluids. These precipitated nanoparticles can potentially act as nano-fins. Hence, in this study molecular dynamic simulations are performed to study the interfacial thermal resistance between a nanofin and a working fluid. A (5, 5) carbon nanotube (CNT) of diameter 6.78 A and various lengths are immersed in various fluids in these analyses. For this simulation the total numbers of the fluid molecules, and the breath and the height of the cell are kept constant. So due to the different densities of the matrix, the length of the cell as well as the length of the nanotube is different for each matrix. In these simulations, the nanotube is placed at the centre of the cell and the fluid molecules surround the nanotube. Periodic boundary conditions are applied in all the directions. So the system under consideration is array of long nanotubes aligned in the horizontal direction. Simulation procedure consists of first minimizing the system. During the minimization the system is allowed to relax. During the simulations, nanotube and water molecules are allowed to move but the cell size remains constant. After minimization, NVT process is performed for 10ps to scale the velocities so that the average temperature of the cell is 300K. After the ensemble is equilibrated to the base temperature of 300K, the temperature of the nanotube is raised to 750K, by scaling the velocities of the carbon atoms. In the next step the system is allowed to relax under constant energy. This is done by performing the NVE equilibration for 10ps. The difference in the temperature of the carbon nanotube and the fluid is then calculated and plotted against the equilibration time. For the CNT-fluid system, the temperature decreases exponentially with time as predicted by various researchers in the literature. From the graphs the interfacial resistance for 1-Hexene, 1,7-Dodecene and 1,7,13-Octadecene is estimated and the effect of polymer chains is investigated. Copyright © 2008 by ASME.

author list (cited authors)

  • Singh, N., Banerjee, D., & ASME, ..

publication date

  • September 2009