Increment of mixing quality of Newtonian and non-Newtonian fluids using T-shape passive micromixer: numerical simulation


In this paper, a T-shape microchannel containing a mixing unit inserted in the straight main channel is designed to increase the mixing quality by geometrical changings in the mixing unit. Governing equations on flow field and concentration field have been discretized and solved using finite element method. Obtained numerical results were validated by comparing the numerical data reported in literature which show acceptable agreement. A MQ parameter based on the concentration variation of the mixture is employed to evaluate the mixing quality in the micromixer. The PI factor is also represented to check the increment in mixing quality with reference to hydraulic parameters. The effect of the number of mixing unit periods and curvature of the obstacles located in mixing unit on the MQ and PI factors have been investigated. The numerical results indicate that the type II gives better PI, so it has been chosen as the main case for the rest of study. On the other hand, the number of mixing unit periods was increased up to 25 for the type II. The results show that the best mixing quality (85.8%) has been obtained when 25-period mixing unit has been used. Also, noticeable mixing quality (81.2%) has been achieved for blood as working fluid using the proposed micromixer which could make it suitable for all chemical systems.

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C :

Concentration (mol/m3)

D :

Diffusion coefficient (m2/s)

J :

Mass flux (kg/m2s)

MQ :

Mixing quality

N :

Power law index

P :

Pressure (Pa)

PI :

Performance index

\(\Delta P\) :

Pressure difference (Pa)

V :

Velocity (m/s)

\(\dot{\gamma }\) :

Shear rate (1/s)

\(\lambda\) :

Relaxation time (s)

\(\mu\) :

Dynamic viscosity (Pa s)

\(\mu_{0}\) :

Zero shear-rate viscosity (Pa s)

\(\mu_{\infty }\) :

Infinite shear-rate viscosity (Pa s)

\(\rho\) :

Density (kg/m3)

\(\sigma\) :

Variation of the concentration in mixture (mol/m3)

i :

ith species of the mixture

mean :

Mean value

max :

Maximum value


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Correspondence to Habib Jalili.

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Fallah, D.A., Raad, M., Rezazadeh, S. et al. Increment of mixing quality of Newtonian and non-Newtonian fluids using T-shape passive micromixer: numerical simulation. Microsyst Technol (2020).

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