A Molecular Dynamics Simulation for Thermal Conductivity Evaluation of Carbon Nanotube-Water Nanofluids

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
M. J. Javanmardi ◽  
K. Jafarpur

A nanofluid model is simulated by molecular dynamics (MD) approach. The simulated nanofluid has been a dispersion of single walled carbon nanotubes (CNT) in liquid water. Intermolecular force in liquid water has been determined using TIP4P model, and, interatomic force due to carbon nanotube has been calculated by the simplified form of Brenner's potential. However, interaction between molecules of water and atoms of carbon nanotube is modeled by Lennard-Jones potential. The Green–Kubo method is employed to predict the effective thermal conductivity of the nanofluid, and, effect of temperature is sought. The obtained results are checked against experimental data, and, good agreement between them is observed.

Author(s):  
Toshihiro Kaneko ◽  
Kenji Yasuoka ◽  
Ayori Mitsutake ◽  
Xiao Cheng Zeng

Multicanonical molecular dynamics simulations are applied, for the first time, to study the liquid-solid and solid-solid transitions in Lennard-Jones (LJ) clusters. The transition temperatures are estimated based on the peak position in the heat capacity versus temperature curve. For LJ31, LJ58 and LJ98, our results on the solid-solid transition temperature are in good agreement with previous ones. For LJ309, the predicted liquid-solid transition temperature is also in agreement with previous result.


Author(s):  
Mohsen Motamedi ◽  
AH Naghdi ◽  
SK Jalali

Composite materials have become popular because of high mechanical properties and lightweight. Aluminum/carbon nanotube is one of the most important metal composite. In this research, mechanical properties of aluminum/carbon nanotube composite were obtained using molecular dynamics simulation. Then, effect of temperature on stress–strain curve of composite was studied. The results showed by increasing temperature, the Young’s modulus of composite was decreased. More specifically increasing the temperature from 150 K to 620 K, decrease the Young’s modulus to 11.7%. The ultimate stress of composite also decreased by increasing the temperature. A continuum model of composite was presented using finite element method. The results showed the role of carbon nanotube on strengthening of composite.


Author(s):  
A. J. H. McGaughey ◽  
J. A. Thomas ◽  
J. Turney ◽  
R. M. Iutzi

We investigate thermal transport in water/carbon nanotube (CNT) composite systems using molecular dynamics simulations. Carbon-carbon interactions are modeled using the second-generation REBO potential, water-water interactions are modeled using the TIP4P potential, and carbon-water interactions are modeled using a Lennard-Jones potential. The thermal conductivities of empty and water-filled CNTs with diameters between 0.83 nm and 1.66 nm are predicted using molecular dynamics simulation and a direct application of the Fourier law. For empty CNTs, the thermal conductivity decreases with increasing CNT diameter. As the CNT length approaches 1 micron, a length-independent thermal conductivity is obtained, indicative of diffusive phonon transport. When the CNTs are filled with water, the thermal conductivity decreases compared to the empty CNTs and transitions to diffusive phonon transport at shorter lengths. To understand this behavior, we calculate the spectral energy density of the empty and water-filled CNTs and calculate the mode-specific group velocities, relaxation times, and thermal conductivity. For the empty 1.10 nm diameter CNT, we show that the acoustic phonon modes account for 65 percent of the total thermal conductivity. This behavior is attributed to their long mean-free paths. When the CNT is filled with water, interactions with the water molecules shorten the acoustic mode mean-free path and lower the overall CNT thermal conductivity.


1996 ◽  
Vol 441 ◽  
Author(s):  
Y. Sasajima ◽  
A. Iijima ◽  
S. Ozawa ◽  
Y. Hiki

AbstractThe phenomenon of surfactant-mediated growth has been successfully simulated by means of a molecular dynamics method using two-dimensional model atoms interacting via a Lennard-Jones potential. Surfactant atoms were placed on a substrate, and then film atoms were deposited. Under adequate experimental conditions, the surfactant atoms could stay at the growing surface by exchanging their positions with the deposited atoms. Effects of various conditions on the morphology of the film surface were precisely investigated by the simulations.


Sign in / Sign up

Export Citation Format

Share Document