Geometric optimization of venturi reactors for enhanced hydrodynamic cavitation efficiency: From conventional to advanced tandem configurations

• CFD-RSM method enabled optimal design of cavitating venturi reactors • Divergence angle is the most influential factor in vapor formation • 28% cavitational enhancement was achieved via Tandem venturi configuration • Study inspires future design of advanced hydrodynamic cavitation reactors This research aims to enhance the efficiency of conventional and tandem cavitating venturis. To address the limitations of conventional hydrodynamic cavitation reactors, such as low degradation efficiency and insufficient vapor formation, a series-arranged venturi system is proposed. Primarily, the impact of three contributing geometric parameters—convergence angle, divergence angle, and throat length—on the performance of a conventional venturi was evaluated and validated. After determining the optimal configuration for a conventional venturi, key geometric considerations were applied to refine the proposed tandem venturi system. The effects of these parameters and interactive effects were analyzed using Response Surface Methodology (RSM). The geometries suggested by RSM were simulated in Ansys Fluent, with the area-weighted average vapor volume fraction along the venturi serving as the objective function. The results revealed that the divergence angle significantly influenced vapor formation and the cavitation zone in the conventional configuration. Ultimately, the optimization process identified the ideal dimensions for the conventional venturi: a convergence angle of 80°, a divergence angle of 8°, and a throat length of 4.65 mm. Utilizing these dimensions as a baseline, the tandem venturi system was optimized, resulting in an internal convergence angle of 40°, an internal divergence angle of 6°, and throat diameters of 4 mm and 8 mm. The optimized tandem venturi achieved a 28% increase in cavitating bubble formation compared to the optimal conventional configuration. This substantial enhancement in bubble formation improves overall cavitation efficiency and expands the cavitation zone.