论文标题

在符合符合粘弹性管中的瞬态压缩流

Transient compressible flow in a compliant viscoelastic tube

论文作者

Anand, Vishal, Christov, Ivan C.

论文摘要

由微电机电系统(MEMS),芯片上的实验室或生物映射软机器人进行的控制器的气动致动,以及对气体和软固体的微流动性的研究,我们分析了瞬态流体结构相互作用(FSIS)在Viscoealastic Plows comperesss compressress compressress comprys complys complys compriage的动机。我们将流体的密度表示为压力的线性函数,并使用润滑近似来进一步简化流体动力学问题。另一方面,结构力学由修改的Donnell Shell理论(kelvin-voigt-type线性粘弹性力学响应)占主导地位。流体和结构力学问题通过管的径向变形和流体力压力耦合。对于较小的可压缩数量和弱耦合,方程是通过扰动扩展来分析求解的。分析了三个说明性问题。首先,我们为稳定流动条件的压力获得了精确的(但隐式)解决方案。其次,我们解决了管入口冲动加压的瞬态问题。第三,我们分析了对振荡入口压力的瞬时响应。我们表明,振荡性入口压力导致管中的声流,这归因于FSI和可压缩性的相互作用引起的非线性压力梯度。此外,我们证明了由于FSI耦合而引起的体积流量的增强。流体动力压力振荡显示出表现出低通频响应(在振荡期间平均时),而管变形的频率响应与带通滤波器的变形相似。

Motivated by problems arising in the pneumatic actuation of controllers for micro-electromechanical systems (MEMS), labs-on-a-chip or biomimetic soft robots, and the study of microrheology of both gases and soft solids, we analyze the transient fluid--structure interaction (FSIs) between a viscoelastic tube conveying compressible flow at low Reynolds number. We express the density of the fluid as a linear function of the pressure, and we use the lubrication approximation to further simplify the fluid dynamics problem. On the other hand, the structural mechanics is governed by a modified Donnell shell theory accounting for Kelvin--Voigt-type linearly viscoelastic mechanical response. The fluid and structural mechanics problems are coupled through the tube's radial deformation and the hydrodynamic pressure. For small compressibility numbers and weak coupling, the equations are solved analytically via a perturbation expansion. Three illustrative problems are analyzed. First, we obtain exact (but implicit) solutions for the pressure for steady flow conditions. Second, we solve the transient problem of impulsive pressurization of the tube's inlet. Third, we analyze the transient response to an oscillatory inlet pressure. We show that an oscillatory inlet pressure leads to acoustic streaming in the tube, attributed to the nonlinear pressure gradient induced by the interplay of FSI and compressibility. Furthermore, we demonstrate an enhancement in the volumetric flow rate due to FSI coupling. The hydrodynamic pressure oscillations are shown to exhibit a low-pass frequency response (when averaging over the period of oscillations), while the frequency response of the tube deformation is similar to that of a band-pass filter.

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