论文标题
低频机械变形的介观液体诱导的热剪切波
Thermal Shear Waves induced in Mesoscopic Liquids at Low Frequency Mechanical Deformation
论文作者
论文摘要
我们表明，在施加低频（Hz）剪切激发时，限制在两个低热电导表面（AL2O3）之间的粘性液体会发出热响应。在施加机械振荡剪切应变后，在大气压和室温下，在大气压和室温下观察到热热波，在100微米到340微米的各种厚度。观察到的热效应与机械激发同步与均匀的粘性流不一致。这表明介质液体能够（部分）在非平衡热力学状态下（部分）转换机械剪切能。这种称为热弹性的效果在固体材料中众所周知。观察到与机械剪切变形的热耦合增强了弹性相关液体分子的假设。热弹性波的幅度通过增加剪切应变幅度到过渡到非线性热行为，在应变行为上与弹性到塑性状态相似，从而线性增加。通过应力测量无法检测到热弹性效应，因此显示为互补的液体动态表征。
We show that a viscous liquid confined between two low thermal conductive surfaces (Al2O3) emit a thermal response upon applying a low frequency (Hz) shear excitation. Hot and cold thermal waves are observed in situ at atmospheric pressure and room temperature, in polypropylene glycol layers of various thicknesses ranging from 100 microns up to 340 microns, upon applying a mechanical oscillatory shear strain. The observed thermal effects, synchronous with the mechanical excitation, are inconsistent with a homogeneous viscous flow. It indicates that mesoscopic liquids are able to (partly) convert mechanical shear energy in non-equilibrium thermodynamic states. This effect called thermoelasticity is well known in solid materials. The observation of a thermal coupling to the mechanical shear deformation reinforces the assumption of elastically correlated liquid molecules. The amplitude of the thermoelastic waves increases linearly by increasing the shear strain amplitude up to a transition to a non-linear thermal behavior, similar in strain behavior to an elastic to plastic regime. The thermo-elastic effects are not detectable via stress measurements and thus appear as a complementary liquid dynamic characterization.
