Authors: D. Trebotich, P. Colella, G. Miller and D. Liepmann
Affilation: Lawrence Livermore National Laboratory, United States
Pages: 520 - 523
Keywords: microfluidics, viscoelasticity
We present a numerical method to model non-Newtonian, viscoelastic flow at the microscale. The equations of motion are the incompressible Navier-Stokes equations coupled with the Oldroyd-B constitutive equation. This constitutive equation is chosen to model a Boger fluid which is representative of complex biological solutions exhibiting elastic behavior due to macromolecules in the solution (e.g., DNA solution). Our numerical approach is a projection method to impose the incompressibility constraint and a Lax-Wendroff method to predict velocities and stresses while recovering both viscous and elastic limits. The method is second-order accurate in space and time, free-stream preserving, has a time step constraint determined by the advective CFL condition, and requires the solution of only well-behaved linear systems amenable to the use of fast iterative methods. We demonstrate the method for viscoelastic incompressible flow in simple microchannels (2D) and microducts (3D).