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采用非平衡分子动力学方法,模拟了含有三角形孔的氮化硼纳米带(BNNR)不同方向的热导率和热整流效应;采用声子波包方法,分析了热整流机理;并结合正交试验设计,考察了温度、串联孔数和三角形孔边长的影响。研究结果表明;带孔纳米带的热导率低于完整纳米带;氮化硼纳米带从三角形孔的顶角到底边的导热能力强于相反方向的,三角形结构所造成的声子透射率差异是产生整流效应的主要原因;随着孔数的增多,热整流效应增强,但由于多孔界面间相互反射的影响,其增强趋势逐渐减缓;随着孔边长的增大,界面散射影响增加,热整流效应明显增强;孔边长因素比孔数对热整流效应的影响更大。
The thermal conductivity and thermal rectification effect in different directions of BNNR containing triangular holes were simulated by unbalanced molecular dynamics method. The thermal rectification mechanism was analyzed by phonon wave packet method. Combined with orthogonal Experimental design, the effects of temperature, the number of tandem holes and the length of the triangular holes were investigated. The results show that the thermal conductivity of the porous nanoribbons is lower than that of the intact nanobelts. The thermal conductivity of the boron nitride nanobelt from the top to the bottom of the triangular holes is stronger than the opposite direction. The difference of phonon transmittance caused by the triangular structure Which is the main reason of the rectification effect. With the increase of the number of holes, the thermal rectification effect is enhanced, but the enhancement tendency gradually decreases due to the mutual reflection between the porous interfaces. With the increase of the hole edge length, the interface scattering effect increases, Thermal rectification effect was significantly enhanced; hole edge length factor than the number of holes on the thermal rectification effect greater.