Dean flow velocity of viscoelastic fluids in curved microchannels

Abstract

Curved microchannels take advantage of inertial and Dean drag forces to achieve size-based separation of particles and cells. Despite the reported numerical and experimental correlations for Dean velocity (VDe) of Newtonian fluids, comprehensive studies and correlations are still required for the flow of viscoelastic fluids in curved microchannels. In this paper, the effects of curved channel height, radius of curvature, and kinematic viscosity were investigated to derive an empirical correlation for VDe of viscoelastic water. The developed knowledge of viscoelastic Dean flow velocity will be vital in design of elasto-inertial microfluidic devices for determination of lateral displacement of fluids in fluid exchange and Dean drag force in particle focusing and separation applications.

Hydrodynamic effect of slip boundaries and exponentially decaying/growing time-dependent pressure gradient on Dean flow

“…Numerical modelling of unsteady flow with time-dependent pressure gradient using one-dimensional Navier-Stokes Equation (NSE) was reported by Azad and Andallah [19]. Other related articles can be seen in references [20][21][22][23].…”

Microparticle manipulation in viscoelastic flows inside curvilinear microchannels: a thorough fundamental study with application to simultaneous particle sorting and washing

“…The required channel length for the first fluid switch (i.e. switching length, L s ) could be obtained using the predicted V De , where 57 Here L R is the average lateral migration of fluid elements, which could be estimated as L R = 0.75 D h . 18 Considering the total channel length of L curve = 5.23 cm (for all radii of curvatures), the number of fluid switches could be roughly estimated as L curve /L s .…”

“…20,49 Ducloue ´et al, 50 Yoon et al 51,52 and others [53][54][55][56] numerically investigated the effect of De number and fluid viscosity on the secondary vortices of shear-thinning fluids in curved microchannels. We experimentally studied the effects of channel geometry and fluid properties on the Dean velocity of shearthinning PEO in water solutions 57 and shear-thickening SiO 2 nanofluids 58 in curvilinear microchannels. A modified empirical correlation was reported with a precise estimation of V De in the viscoelastic PEO solutions, as shown in eqn (3).…”

Continuous Particle Separation Driven by 3D Ag-PDMS Electrodes with Dielectric Electrophoretic Force Coupled with Inertia Force

“…Inertial separation, as the passive sorting method, uses inertial force within the fluid to deflect the trajectory of cells and produce continuous and high-throughput cell separation without applying external forces [21,22]. Commonly used inertial sorting channels include spiral channels [23,24], curved channels [25,26], and contraction-/expansion(CEA) structures [27,28]. The CEA structure can achieve sorting according to the size of the cells or particles at a low Reynolds number, preventing damage to the cells or particles from high shear forces in conventional inertial sorting.…”