Reduced modelling and global instability of finite-Reynolds-number flow in compliant rectangular channels
نویسندگان
چکیده
Experiments have shown that flow in compliant microchannels can become unstable at a much lower Reynolds number than the corresponding rigid conduit. Therefore, it has been suggested wall's elastic compliance be exploited towards new modalities of microscale mixing. While previous studies mainly focused on local instability induced by fluid--structure interactions (FSIs) system, we derive one-dimensional (1D) model to study FSI's effect global instability. The proposed 1D FSI is tailored long, shallow rectangular with deformable top wall, similar experiments. Going beyond usual lubrication flows analyzed these geometries, include finite fluid inertia and couple reduced equations novel wall deformation equation. Although quantitative comparison experiments difficult, behaviors show qualitative agreement experimental observations, capture several key effects. Specifically, find critical conditions under which inflated base state linearly infinitesimal perturbations. numbers predicted are observations. modes highly oscillatory, frequencies close natural frequency suggesting observed instabilities resonance phenomena. Furthermore, during start-up from an undeformed initial state, self-sustained oscillations triggered FSI. Our modeling framework applied other microfluidic systems geometric scale separation different operating conditions.
منابع مشابه
Micromixer based on viscoelastic flow instability at low Reynolds number.
We exploited the viscoelasticity of biocompatible dilute polymeric solutions, namely, dilute poly(ethylene oxide) solutions, to significantly enhance mixing in microfluidic devices at a very small Reynolds number, i.e., Re approximately 0.023, but large Peclet and elasticity numbers. With an abrupt contraction microgeometry (8:1 contraction ratio), two different dilute poly(ethylene oxide) solu...
متن کاملElectroviscous Effects in Low Reynolds Number Flow through a Microfluidic Contraction with Rectangular Cross-Section
The electrokinetic flow resistance (electroviscous effect) is predicted for steady state, pressure-driven liquid flow at low Reynolds number in a microfluidic contraction of rectangular cross-section. Calculations of the three dimensional flow are performed in parallel using a finite volume numerical method. The channel walls are assumed to carry a uniform charge density and the liquid is taken...
متن کاملDrag coefficient and strouhal number analysis of a rectangular probe in a two-phase cross flow
In some case of laboratory and industrial applications, various kind of measurement instruments must be placed in a conduit, in which multiphase fluid flows. Vortex shedding for any immersed body in flow field is created with a frequency, which according to flow conditions such as flow rates, geometry of body, etc. may be constant or variable. Failure may happen, if this frequency is close to o...
متن کاملMigration and deformation of bubbles rising in a wall-bounded shear flow at finite Reynolds number
The quasi-steady migration and deformation of bubbles rising in a wall-bounded linear shear flow are investigated experimentally in the low-but-finite-Reynolds-number regime. A travelling optical device that follows the bubble is used for this purpose. This apparatus allows us to determine accurately the bubble radius, contour and rising speed, together with the distance between the bubble and ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Journal of Fluid Mechanics
سال: 2022
ISSN: ['0022-1120', '1469-7645']
DOI: https://doi.org/10.1017/jfm.2022.802