CFD Evaluation of a Tesla-Type Micromixer for Chemical Processing

Passive Tesla-type micromixers achieve very good mixing in published studies, yet they are rarely found in industrial flow reactors. This study evaluates whether a modified Tesla micromixer could be suitable for continuous chemical processing by considering mixing quality together with pressure drop and throughput. A three-dimensional model with four pairs of Tesla units (channel width 200 µm, depth 110 µm) was built from published dimensions and simulated as a transient, incompressible, laminar water flow in SimScale at Reynolds numbers of 10, 50 and 70. Mixing of the two inlet streams was tracked with a passive scalar. At Re = 10 the streams mixed gradually, while at Re = 50 and Re = 70 they were fully mixed after about two of the eight units, consistent with a transition from diffusion- to convection-dominated mixing. However, as Re increased from 10 to 70, the flow rate increased about 7 times while the pressure drop increased about 29 times (from 2.7 to 78.2 kPa), so the pumping power increased about 200 times. One mixer processed at most about 80 mL per hour, and at Re ≥ 50 low-velocity regions formed inside the bends. The results suggest that the Tesla micromixer is limited not by mixing but by low throughput per unit, rapidly rising pressure drop and possible blockage, and that operation near Re = 50 with fewer units would be the most efficient choice.