The study of the mass and heat transfer phenomena in micro-nano devices and systems (MEMS/NEMS) very often involves polyatomic gas flows in long capillaries. In the case of polyatomic gases, the internal degrees of freedom of gas molecules may have a significant effect on the macroscopic quantities of practical interest. The scope of the present study is two-fold. First, an accurate methodology for calculating the mass and heat flow rate coefficients is proposed based on a simple kinetic model proposed by Holway. The proposed methodology is based on the available experimental data in the literature and allows overcoming the well-known limitation of the Holway model to describe all the transport coefficients simultaneously. Second, the proposed methodology is applied to investigate the rarefied polyatomic gas flows through long micro- and nanotubes under temperature and pressure differences taking into account the translational, rotational and vibrational degrees of freedom of the gas molecules on the basis of the Holway kinetic model. Results are presented for N₂, CO₂, CH₄ and SF₆ representing linear and non-linear, but always non-polar molecules in a wide range of the gas temperature. The mass flow rates of the polyatomic gases in the temperature-driven flow differ significantly from the corresponding monatomic ones, with the difference reaching a maximum of about 25% for the examined gases and temperatures varied between 300 and 1000 K. The maximum relative deviation between monatomic and polyatomic heat flow rates can reach 39%, 64%, 73% and 87% for N₂, CO₂, CH₄ and SF₆, respectively. The results are compared against the corresponding published ones based on the Rykov model highlighting the very good agreement between the two models and the accuracy of the proposed methodology for the calculation of the mass and heat flow coefficients is confirmed.

对微纳米器件和系统（MEMS / NEMS）中的传质和传热现象的研究通常涉及长毛细管中的多原子气流。在多原子气体的情况下，气体分子的内部自由度可能会对实际应用中的宏观量产生重大影响。本研究的范围有两个方面。首先，基于Holway提出的简单动力学模型，提出了一种精确的计算质量和热流率系数的方法。所提出的方法基于文献中的可用实验数据，并允许克服Holway模型同时描述所有传输系数的众所周知的局限性。第二，所提出的方法用于在Holway动力学模型的基础上，考虑到气体分子的平移，旋转和振动自由度，在温度和压力差下研究稀有多原子气体在长微管和纳米管中的流动。结果显示为N_在图2中，CO ₂，CH ₄和SF ₆代表在宽广的气体温度范围内的线性和非线性分子，但总是非极性分子。温度驱动流中多原子气体的质量流量与相应的单原子气体的质量流量显着不同，对于所检查的气体，温度在300至1000 K之间变化，该差异达到最大约25％。 N ₂，CO ₂，CH ₄和SF _6的单原子和多原子热流率可以达到39％，64％，73％和87％， 分别。将结果与基于Rykov模型的相应出版物进行了比较，突出了两个模型之间的良好一致性，并确认了所提出的质量和热流系数计算方法的准确性。