A Drag-Reduction Mechanism of Seagull-Inspired Curved Vortex Generators Integrating Response Surface Method and Genetic Algorithms Optimization in Compact Heat Exchangers

The vortex generator is extensively utilized to enhance the air-side flow and heat transfer in compact heat exchangers, attributed to its high efficiency and low friction factor. This paper contains an innovative design of biomimetic vortex generators (BVGs), characterized by a distinct variable curvature and orientation. The curvatures and orientations, serving as key parameters for this innovative design, were collaboratively optimized using a combination of the response surface method and the non-dominated sorting genetic algorithm II, while the friction factor and Colburn factor serve as objective functions. The research findings indicate that the use of BVGs significantly reduces the friction factor, and the optimal curvature parameters for various orientations have been determined. The enhanced heat transfer mechanism associated with BVGs is attributed to their capacity to generate multiple longitudinal vortex structures downstream, with analogous secondary flow structures forming across different orientations. A comprehensive evaluation metric reveals that BVGs achieve an improvement exceeding 50% in performance compared to other high-performance vortex generators. These findings introduce an entirely novel configuration for vortex generators, which is anticipated to significantly advance the development of flow and heat transfer enhancement in compact heat exchangers.