两平板间两组分稀薄气体振荡传热的数值模拟

Numerical Simulation of Oscillating Heat Transfer of Rarefied Binary Gas Between Two Plates

采用离散统一气体动理学方法(DUGKS)求解两组分气体McCormack模型,模拟下板温度周期波动激发的两平板间两组分稀薄气体流动与传热问题,分析系统稀薄参数、温度变化频率以及组分摩尔浓度对平板间流动与传热现象的影响。数值结果表明:两平板间气体流动与传热呈现周期变化,并且平板间存在最小局部温度的现象,其位置与系统稀薄程度呈正比,此外热渗透深度随着稀薄参数的减小而减小。热渗透深度随轻组分浓度的增大而先增大,在轻组分浓度为0.6左右达到最高值,最后减小并与单组分气体结果一致。

In this paper,the discrete unified gas kinetic scheme(DUGKS)is used to solve the McCormack model of binary gas,simulate the flow and heat transfer of rarefied binary gas between two plates excited by the periodic fluctuation of lower plate temperature,and analyze the effects of system rarefied parameters,temperature change frequency and component molar concentration on the flow and heat transfer between plates.The numerical results show that the gas flow and heat transfer between the two plates change periodically,and we find that the minimum local temperature exists between the plates,and its position is inversely proportional to the degree of system thinning.In addition,it is found that the thermal penetration depth decreases with the increase of the rarefaction parameter.The heat penetration depth first increases with the increase of light component concentration,reaches the highest value when the light component concentration is about O.6,and finally decreases and is consistent with the result of single component gas.