摘要
采用经典分子动力学方法探索了电场强度和富勒烯纳米颗粒浓度对水-富勒烯纳米流体在石墨烯纳米孔隙中Couette剪切流动特性的影响机理。结果表明:当剪切应变率超过临界剪切应变率时,边界滑移速率迅速增加,且临界剪切应变率随着电场强度的增强而增大;边界滑移速率和流体黏性值都随着富勒烯体积分数的增加而增大。当电场强度较小时,流体的流动表现为边界正滑移,但当电场强度达到临界值时,流体的流动存在边界负滑移;边界滑移速率先随着电场强度的增强而减小,直至电场强度达到临界值后,边界滑移速率随着电场强度的增强先减小后增大。富勒烯纳米流体的黏性值先随着电场强度的增强而增大,而当电场强度达到临界值后,纳米流体的黏性值则随电场强度的增强呈现先减小而后增大的趋势。
The effect mechanisms of the electric field intensity and fullerene nanoparticle concentration on the Couette flow motion behaviors of water-fullerene nanofluids in graphene nanochannels were investigated by using classical molecular dynamics simulations.The results indicate that the boundary slip velocity increases abruptly when the shear strain rate is above a threshold,and the critical shear strain rate increases with the increase of the electric field intensity.Both the boundary slip velocity and the fluid viscosity increase with the increase of the fullerene volume fraction.There exists the positive slippage at the boundaries when the electric field intensity is relatively weaker,while the negative slippage appears as the electric field intensity reaches the critical value.The boundary slip velocity decreases with the increase of the electric field intensity,but with the increase of the electric field intensity,the boundary slip velocity decreases first until the electric field intensity is above a threshold,and then increases.The viscosity of the fullerene nanofluid increases with the increase of the electric field intensity.However,when the electric field intensity increases above a threshold,the viscosity of the nanofluid decreases first and then increases with the increase of the electric field intensity.
出处
《微纳电子技术》
北大核心
2017年第7期451-457,共7页
Micronanoelectronic Technology
基金
国家自然科学基金面上项目(11472117
11372298
51675236)
