On the damping effect of gas rarefaction on propagation of acoustic waves in a microchannel
On the damping effect of gas rarefaction on propagation of acoustic waves in a microchannel
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气体稀薄对微通道内声波传播的阻尼效应
DOI：
10.1063/1.4866443
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发表时间：
2014
影响因子：
4.6
通讯作者：
L. Pogorelyuk
中科院分区：
文献类型：
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作者：
A. Manela;G. Radtke;L. Pogorelyuk
我们考虑微通道中的气体的响应，其边界在正常方向上的瞬时（小振幅）的非周期性运动。该问题是制定一个理想的单原子气体使用Bhatnagar，格罗斯和Krook（BGK）动力学模型，并解决了整个范围内的努森（Kn）数。分析结合了分析（无碰撞和连续极限）解决方案与数值（低方差蒙特卡罗和线性化BGK）计算。由边界运动驱动的气流由一系列传播和反射的压力波组成，随时间衰减到最终平衡状态。气体稀薄对平衡过程有“阻尼效应”，平衡所需的时间随Kn的增加而缩短。在连续极限下表征气体响应的流体力学量的振荡在无碰撞条件下消失。有两个移动的边界的影响，相比之下，只有一个考虑在以前的研究中的时间间隔…
We consider the response of a gas in a microchannel to instantaneous (small-amplitude) non-periodic motion of its boundaries in the normal direction. The problem is formulated for an ideal monatomic gas using the Bhatnagar, Gross, and Krook (BGK) kinetic model, and solved for the entire range of Knudsen (Kn) numbers. Analysis combines analytical (collisionless and continuum-limit) solutions with numerical (low-variance Monte Carlo and linearized BGK) calculations. Gas flow, driven by motion of the boundaries, consists of a sequence of propagating and reflected pressure waves, decaying in time towards a final equilibrium state. Gas rarefaction is shown to have a “damping effect” on equilibration process, with the time required for equilibrium shortening with increasing Kn. Oscillations in hydrodynamic quantities, characterizing gas response in the continuum limit, vanish in collisionless conditions. The effect of having two moving boundaries, compared to only one considered in previous studies of time-peri...