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The molecular dynamic simulation on impact and friction characters of nanofluids with many nanoparticles system.

Lv J, Bai M, Cui W, Li X - Nanoscale Res Lett (2011)

Bottom Line: The Cu-Ar nanofluid model consisted of eight spherical copper nanoparticles with each particle diameter of 4 nm and argon atoms as base liquid.The Lennard-Jones potential function was adopted to deal with the interactions between atoms.In this process, agglomeration of nanoparticles was very apparent, with the pressure increasing, the phenomenon became more prominent.

View Article: PubMed Central - HTML - PubMed

Affiliation: State Key Laboratory of Structural Analysis for Industrial Equipment, Department of Engineering Mechanics, Dalian University of Technology, Dalian 116024, China. lvjizu2002@yahoo.com.cn.

ABSTRACT
Impact and friction model of nanofluid for molecular dynamics simulation was built which consists of two Cu plates and Cu-Ar nanofluid. The Cu-Ar nanofluid model consisted of eight spherical copper nanoparticles with each particle diameter of 4 nm and argon atoms as base liquid. The Lennard-Jones potential function was adopted to deal with the interactions between atoms. Thus motion states and interaction of nanoparticles at different time through impact and friction process could be obtained and friction mechanism of nanofluids could be analyzed. In the friction process, nanoparticles showed motions of rotation and translation, but effected by the interactions of nanoparticles, the rotation of nanoparticles was trapped during the compression process. In this process, agglomeration of nanoparticles was very apparent, with the pressure increasing, the phenomenon became more prominent. The reunited nanoparticles would provide supporting efforts for the whole channel, and in the meantime reduced the contact between two friction surfaces, therefore, strengthened lubrication and decreased friction. In the condition of overlarge positive pressure, the nanoparticles would be crashed and formed particles on atomic level and strayed in base liquid.

No MeSH data available.


Related in: MedlinePlus

Relationship between h and simulation time.
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Figure 4: Relationship between h and simulation time.

Mentions: After relaxation, symmetry boundaries are still applied along the x- and y-directions. From 600 to 4200 ps, the upper plate is given constant translational velocities of 100 m/s on y-axis and the lower one is still fixed to perform impact and friction simulation. As shown in Figure 1 both plates mutually compress. 600 to 1600 ps are for impact process and 1600 to 4200 ps are for friction simulation, respectively. Two cases have been designed to examine the effect of pressure. The only difference between them is that in case 1 H changes from 14.8 to 8.8 nm and in case 2 it changes to 7.5 nm. The length of time step is the same as relaxation, and the total computer running time during impact and friction simulation takes about 145 h. Figure 4 shows the relationship between h and simulation time.


The molecular dynamic simulation on impact and friction characters of nanofluids with many nanoparticles system.

Lv J, Bai M, Cui W, Li X - Nanoscale Res Lett (2011)

Relationship between h and simulation time.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211256&req=5

Figure 4: Relationship between h and simulation time.
Mentions: After relaxation, symmetry boundaries are still applied along the x- and y-directions. From 600 to 4200 ps, the upper plate is given constant translational velocities of 100 m/s on y-axis and the lower one is still fixed to perform impact and friction simulation. As shown in Figure 1 both plates mutually compress. 600 to 1600 ps are for impact process and 1600 to 4200 ps are for friction simulation, respectively. Two cases have been designed to examine the effect of pressure. The only difference between them is that in case 1 H changes from 14.8 to 8.8 nm and in case 2 it changes to 7.5 nm. The length of time step is the same as relaxation, and the total computer running time during impact and friction simulation takes about 145 h. Figure 4 shows the relationship between h and simulation time.

Bottom Line: The Cu-Ar nanofluid model consisted of eight spherical copper nanoparticles with each particle diameter of 4 nm and argon atoms as base liquid.The Lennard-Jones potential function was adopted to deal with the interactions between atoms.In this process, agglomeration of nanoparticles was very apparent, with the pressure increasing, the phenomenon became more prominent.

View Article: PubMed Central - HTML - PubMed

Affiliation: State Key Laboratory of Structural Analysis for Industrial Equipment, Department of Engineering Mechanics, Dalian University of Technology, Dalian 116024, China. lvjizu2002@yahoo.com.cn.

ABSTRACT
Impact and friction model of nanofluid for molecular dynamics simulation was built which consists of two Cu plates and Cu-Ar nanofluid. The Cu-Ar nanofluid model consisted of eight spherical copper nanoparticles with each particle diameter of 4 nm and argon atoms as base liquid. The Lennard-Jones potential function was adopted to deal with the interactions between atoms. Thus motion states and interaction of nanoparticles at different time through impact and friction process could be obtained and friction mechanism of nanofluids could be analyzed. In the friction process, nanoparticles showed motions of rotation and translation, but effected by the interactions of nanoparticles, the rotation of nanoparticles was trapped during the compression process. In this process, agglomeration of nanoparticles was very apparent, with the pressure increasing, the phenomenon became more prominent. The reunited nanoparticles would provide supporting efforts for the whole channel, and in the meantime reduced the contact between two friction surfaces, therefore, strengthened lubrication and decreased friction. In the condition of overlarge positive pressure, the nanoparticles would be crashed and formed particles on atomic level and strayed in base liquid.

No MeSH data available.


Related in: MedlinePlus