Mithun Kanchan and Ranjith Maniyeri* Pages 118 - 125 ( 8 )
Background: Fluid flow in microchannels is restricted to low Reynolds number regimes and hence inducing chaotic mixing in such devices is a major challenge. Over the years, the Immersed Boundary Method (IBM) has proved its ability in handling complex fluid-structure interaction problems.Objectives: Inspired by recent patents in microchannel mixing devices, we study passive mixing effects by performing two-dimensional numerical simulations of wavy wall in channel flow using IBM. Methods: The continuity and Navier-Stokes equations governing the flow are solved by fractional step based finite volume method on a staggered Cartesian grid system. Fluid variables are described by Eulerian coordinates and solid boundary by Lagrangian coordinates. A four-point Dirac delta function is used to couple both the coordinate variables. A momentum forcing term is added to the governing equation in order to impose the no-slip boundary condition between the wavy wall and fluid interface. Results: Parametric study is carried out to analyze the fluid flow characteristics by varying amplitude and wavelength of wavy wall configurations for different Reynolds number. Conclusion: Configurations of wavy wall microchannels having a higher amplitude and lower wavelengths show optimum results for mixing applications.
Dirac delta function, fractional-step method, immersed boundary method, momentum forcing, passive mixing, wavy walled microchannel.
Biophysics Laboratory, Department of Mechanical Engineering, National Institute of Technology Karnataka, Surathkal, Mangalore-575025, Biophysics Laboratory, Department of Mechanical Engineering, National Institute of Technology Karnataka, Surathkal, Mangalore-575025