NUMERICAL INVESTIGATION OF THE MIXING MECHANISM OF PASSIVE MICROMIXER WITH TESLA STRUCTURE

Abstract

Passive micromixers using Tesla structures are commonly used in microfluidic systems for efficient fluid mixing. To understand the mixing mechanism of such micromixers, numerical investigations can be performed using computational fluid dynamics (CFD) simulations. In this study, we aimed to improve the mixing mechanism in microfluidic applications using the Tesla valve, which is a static valve that allows the flow of liquids in only one direction. The study analyzed the effect of fluid inlet velocity and surface roughness on the mixing performance of a numerical model. The model was used to test a mixture of water and blood at four flow velocities: 0.15, 0.35, 0.5, and 1.0 m/s. Additionally, the study evaluates the effect of surface roughness on mixing performance by assigning a uniform roughness value of 12 µm to all surfaces in the model. The results showed that fluid mixing primarily occurred in the curved portions of the model, while fluid streams remained separate in the straight segments. There was no backflow, indicating successful fluid transmission without the need for additional valves or switches. The study also includes three cross-sections designated as cross-sections #1, #2, and #3, each at a vertical distance of 0.55 mm, 1.00 mm, and 1.75 mm from the inlet, respectively, to visualize the impact of surface roughness on mixing quantitatively. Overall, the study demonstrated that two Tesla structures can efficiently mix different fluid types, and the Tesla valve is scalable, durable, and easy to fabricate in various materials for microfluidic applications.

Keywords

• Passive micromixers
• microfluidic devices
• Tesla valve
• surface roughness
• fluid mixing

References

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