Thermal conductivity enhancement of paraffin by adding boron nitride nanostructures: A molecular dynamics study

2017 ◽  
Vol 110 ◽  
pp. 1411-1419 ◽  
Author(s):  
Changpeng Lin ◽  
Zhonghao Rao
Author(s):  
K. Raji ◽  
C. B. Sobhan ◽  
Jaime Taha-Tijerina ◽  
T. N. Narayanan ◽  
P. M. Ajayan

In applications such as coolants in electrical devices, in addition to high heat transfer capabilities, the cooling fluids are required to have low electrical conductivity also. As nanoparticle suspensions (nanofluids) show excellent thermal performance due to enhanced thermal conductivity, it would be advantageous to evolve nanofluid-coolants, which are electrically insulating also, for such applications. A theoretical analysis of one such suspension is performed in the present work, to evaluate the thermal conductivity enhancement due to the presence of nanoparticles in the base fluid. The nanofluid analyzed is a suspension of hexagonal boron nitride (h-BN) in mineral oil, for application as a cooling fluid in electrical transformers. The thermal conductivity of the boron nitride suspension is computed using equilibrium Molecular Dynamics (MD) simulations followed by the application of the Green-Kubo auto correlation function. The Lennard–Jones potentials and simple harmonic oscillation potentials are used as the intermolecular potentials to appropriately describe the various atomic and molecular interactions in the boron nitride suspension. The molecular dynamics simulations are performed using LAMMPS software. The computational results are benchmarked with experimental findings on the thermal conductivity enhancement in the suspension at various temperatures and concentrations of nanoparticles, obtained using a transient measurement technique.


2017 ◽  
Vol 9 (17) ◽  
pp. 14555-14560 ◽  
Author(s):  
Lin Jing ◽  
Majid Kabiri Samani ◽  
Bo Liu ◽  
Hongling Li ◽  
Roland Yingjie Tay ◽  
...  

Author(s):  
C. B. Sobhan ◽  
Nithin Mathew ◽  
Rahul Ratnapal ◽  
N. Sankar

A theoretical methodology based on molecular dynamics modeling, for the estimation of the enhancement of the thermal conductivity of fluids by the introduction of suspended metallic nanoparticles is proposed here. This involves the process of generating the atomic trajectories of a system of a finite number of particles by direct integration of the classical Newton’s equations of motion, with appropriate interatomic potentials and application of suitable initial and boundary conditions. Algorithms are made for simulating the nanofluid abiding the procedural steps of the Molecular Dynamics method. The method is presented as a means to solve the generic problem of thermal conductivity enhancement of liquids in the presence of nanoparticles, and illustrated using a specific simulation procedure with properties representing water and platinum nanoparticles. The thermal conductivity enhancement in the base fluid due to suspension of nanoparticles, estimated using Molecular dynamics simulations are compared with existing experimental results and those predicted by conventional effective medium theories. Parametric studies are conducted to obtain the variation of thermal conductivity enhancement with the temperature, and the volume fraction of the nanoparticles in the suspension.


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