The present master thesis addresses the problem of efficient mixing of fluids in microchannels where no turbulent mixing is present due to laminar flow. The primary focus of this study is a passive micromixer with inclined grooves, wherein the mixing process is predominantly attributed to diffusion and chaotic convection. The objective of the research was to optimise the geometry of the micromixer grooves with a view to enhancing the mixing process. To this end, simulations were conducted utilising the computational fluid dynamics method in Ansys Fluent. In order to validate the numerical model, a comparison with existing literature data was performed, and then experimental validation was conducted using an optimised micromixer fabricated using 3D printing and PDMS casting technology. An analysis of the groove shapes revealed that the geometry with rounded edges allowed for the most efficient mixing. The simulation results demonstrated a high degree of congruence with the experimental data, thereby substantiating the model's validity through the verification of flow pattern matching. This work contributes to the improvement of the design of passive micromixers and related microfluidic devices.
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