ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Design of a micromixer with alternating flattened tubes

Morteza Bayareh, Narges Jafari Ghahfarokhi, and Zahra Ghorbani Kharaji

Department of Mechanical Engineering, Shahrekord University, Shahrekord, Iran

E-mail: m.bayareh@sku.ac.ir

Received: 13 May 2024  Accepted: 11 June 2024

Abstract:

The present paper proposes a novel design for a chaotic micromixer utilizing alternating flattened tubes (AFTs). Three-dimensional Navier–Stokes equations and a convection–diffusion transport equation are solved to perform numerical simulations for a broad Reynolds number (Re) range of 0.1–150. The impact of alternating pitch angle (θ = 30°–75°), Re, and dynamic viscosity (μ = 10⁻³–10⁻¹) on the performance of the AFT micromixer is assessed. The results reveal that the mixing index is improved with θ due to an enhancement in the molecular diffusion and induced chaotic advection. When Re = 0.1, the AFT micromixer can provide excellent mixing quality compared to a T-shaped micromixer while its pressure drop (Δp) is less than 7 Pa. It is found that molecular diffusion is a dominant mechanism of micromixing when Re is low (0.1) and chaotic advection plays a major role when Re is an order of 10 and 100. The results demonstrate that mixing energy cost is reduced by increasing θ when Re is kept constant, meaning that higher mixing quality can be achieved by enhancing θ while Δp increases slightly.

Keywords: Microfluidics; AFT micromixer; Mixing index; Pressure drop; Mixing energy cost

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-024-03564-6

Chemical Papers 78 (11) 6663–6670 (2024)