Dynamic Flow Behavior of Viscoelastic Fluids in Microfluidic Devices

In the natural world, intricate fluids are not only present but are also purposefully crafted for specific applications. This craftsmanship involves introducing macromolecules into a solvent, among other techniques, imparting viscoelasticity to the fluid. Viscoelasticity, a distinctive property of such fluids, leads to a myriad of flow instabilities and substantial alterations in fluid dynamics. These fluids belong to a category that exhibits both viscous and elastic characteristics. The modeling of viscoelastic fluids necessitates the formulation of constitutive equations for stress. Selecting the most fitting constitutive relationship can be a challenging task due to the nuanced nature of these fluids. Therefore, The focus of this study is the unsteady flow of Oldroyd-B and FENE-P viscoelastic fluid within a wavy microfluidic channel. A numerical analysis has been performed to study the combined effects of fluid elasticity and channel geometry parameters on flow characteristics, particularly at a low Reynolds number. The computations were carried out using the finite-volume-based open-source solver OpenFOAM®. The findings contribute to our understanding of the interplay between fluid properties and channel design in microfluidic systems.