Flow characterization in periodic microchannels containing asymmetric grooves

Osorio Nesme A, Delgado A (2017)

Publication Type: Journal article

Publication year: 2017

Journal

Fluid Dynamics Research Institute of Physics

Publisher: Institute of Physics Publishing

Book Volume: 49

Pages Range: 055502

Journal Issue: 5

DOI: 10.1088/1873-7005/aa7a35

Abstract

Characterization of two-dimensional flows in microchannels with anisotropic periodic grooves is numerically carried out by using the lattice Boltzmann method. Periodically placed microstructures, consisting of novel nozzle-diffuser-like grooves are deliberately designed to introduce a flow-direction dependent resistance. Simulations were conducted for a low-to-moderate Reynolds number in the laminar-transition flow regime. Different channel geometries, defined by the half-angle phgr of the periodic grooves are considered. The influence of the half-angle on both the flow field and the onset of oscillatory flow regime at different driving body forces is analyzed. At a low Reynolds number, the flow is observed stationary and fully reversible, regardless of the groove geometry. In this regime, higher Reynolds numbers were observed when the geometry acts as a diffuser (negative flow) than as a nozzle (positive flow) for a given driving body force. At sufficiently high Reynolds number the flow turns from a steady state to a time-dependent oscillatory regime through a Hopf bifurcation. Successive flow bifurcations lead the flow structure from a periodic regime to a quasi-chaotic regime with three-dimensional structures. The onset of unsteady flow occurs earlier for positive flows and geometries with small half-angles. For higher driving forces, there is a reduction in the volume flow rate due to the advected material in the transversal direction, causing consequently a decrease in the Reynolds number.

Authors with CRIS profile

Anuhar Osorio Nesme Lehrstuhl für Strömungsmechanik (LSTM) Antonio Delgado Lehrstuhl für Strömungsmechanik (LSTM)

How to cite

APA:

Osorio Nesme, A., & Delgado, A. (2017). Flow characterization in periodic microchannels containing asymmetric grooves. Fluid Dynamics Research, 49(5), 055502. https://doi.org/10.1088/1873-7005/aa7a35

MLA:

Osorio Nesme, Anuhar, and Antonio Delgado. "Flow characterization in periodic microchannels containing asymmetric grooves." Fluid Dynamics Research 49.5 (2017): 055502.

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