A Reversible Miniaturized Tesla Valve

Abstract Tesla valves are passive fluid diodes originally proposed in 1920 by Nikola Tesla and consist of parallel tubes with bifurcated sections that rectify flow using fluid dynamics principles. Unlike conventional Tesla valves which are fixed in shape and offer a specific preset diodicity, the novel concept presented here provides a Tesla valve with adjustable diodicity capable of reversing the flow direction to promote flow in the backward direction rather than the forward direction. This reversibility is achieved by applying external stress that changes the valve's preferential flow. Through an integrated workflow, Tesla valve diodicity is evaluated under external uniaxial compression or tension for low Reynolds numbers ranging between 10 and 300. Findings reveal that the diodicity of the valve decreases below one under sufficient uniaxial compression. These results suggest the potential for reversing the valve's functionality under specific conditions, promoting less resistant flow in the reverse direction than the forward direction. Oppositely, applying tension to the Tesla valve increases the diodicity of the valve to up to 4.38, representing an increase of 89.6% in valve's diodicity compared to the undeformed valve. Moreover, a diodicity value of 1.57 is achieved at a Reynolds number of 30 upon applying 20% strain in tension. Such a reversible valve can be made of flexible material and will provide additional potential applications for the valve where the direction of the flow needs to be fine-tuned.