基于分子动力学的板叠间传热传质微观机理的研究

Study on Microscopic Mechanism of Heat and Mass Transfer between Plates Based on Molecular Dynamics Simulation

摘要: 本文采用分子动力学计算方法从微观上对热声发动机板叠间的传热传质机理及其起振频率进行了模拟研究。在往复振荡过程中，由于温度梯度的存在，使得能量面发生了迁移，最终在冷热气体间产生密度梯度，直至密度梯度为零时完成一个周期。自激振荡伴随有能量耗散，故而温度波峰与波谷随着周期数的增加逐渐减小。随着温度比的升高，起振频率逐渐降低，这将有利于微通道板叠结构缩短谐振管的长度，实现结构的微型化。

Abstract: In this paper, the mechanism of heat and mass transfer between thermoacoustic engine plates and the starting frequency are studied by molecular dynamics method. In the process of reciprocating oscillation, due to the existence of temperature gradient, the energy surface is transferred, and fi-nally a density gradient is generated between hot and cold gases until the density gradient is zero. The self-excited oscillation is accompanied by energy dissipation, so the temperature peaks and troughs decrease with the increase of period number. With the increase of the temperature ratio, the starting frequency decreases gradually, which will help the microchannel stack structure shorten the length of the resonance tube and realize the microminiaturization of the engine.