Lin, J.; Zhao, D.; Guo, C.; Zhang, Z., and Su, Y., 2020. Numerically modeling the effect of flexibility on flow around marine engineering structures: Using the shape of the saguaro cactus. Journal of Coastal Research, 36(3), 628–635. Coconut Creek (Florida), ISSN 0749-0208.

The cylinder is an essential infrastructure with a wide range of applications in the engineering fields of shipping, aviation, and construction. The study of the hydrodynamic performance of a cylinder is a current research focus that can provide a more direct reference for the optimized design of its structure. In this study, the principles of bionics and flexible materials are applied to the research of marine structures, and the shape of the saguaro cactus is used as a reference. Considering the influence of flexible materials, a numerical simulation that provides a new route for the research and design of cylinders in the engineering field is performed. Based on the morphological characteristics of the cactus, a three-dimensional model and its fluid-solid control domain are established. Numerical simulations of the flow around rigid and flexible models with different Reynolds numbers are carried out. The lift, drag, flow field characteristics, and structural deformation are obtained. A turbulent vortex street is created by the flow around the cylinder. Vortex-induced vibration is generated, which demonstrates apparent three-dimensional characteristics. In a majority of the cases, flexible materials and irregular cross-sectional shapes have a clear influence on the flow around the cylinder.