Optimization of micro Venturi diode in steady flow at low Reynolds number

Micro Venturi diodes have been broadly used in microfluidics to rectify liquid flow. A key feature of these diodes is that they have no moving parts. This article treats the numerical optimization of such a micro Venturi diode for the case of steady Newtonian flow, with Reynolds numbers less than 100, which typically applies to microfluidic devices. Key design factors are discussed, such as the ratio of length to width of the design domain, the values of lower and upper bounds for the constraint of the volume of the diodes, and the Reynolds number, all of which influence the outcome of the diode effect. Curved micro Venturi diodes are found by the optimization. The method presented provides a systematic way to design Venturi diodes for steady Newtonian flows.