Yunus Celik, Burhan Necati Kiziloglu
Computer Modeling in Engineering & Sciences 2026, 148(1): 15
Published: 27 July 2026
This study investigates the passive amplification of aerodynamic excitation forces through coordinated bluff-body geometric modifications to quantify the vortex-induced vibration (VIV) energy harvesting potential of stationary cylinders in the laminar regime. Two-dimensional laminar simulations on fixed bodies isolate geometric effects from structural feedback. Circumferential biomimetic grooves are first optimised on a circular baseline at using a Taguchi orthogonal array (L9), identifying groove amplitude as the dominant control parameter and selecting , as the optimal configuration, which yields a increase in the root-mean-square lift coefficient ( ) and a Strouhal number reduction relative to the smooth circular baseline. The optimal groove profile is coupled with vertically-oriented bluff elliptical bases at three aspect ratios ( , , and ). Proper Orthogonal Decomposition (POD), wake fluctuation energy (WFE) mapping, and a simplified one-degree-of-freedom (1-DOF) structural projection model quantify the aerodynamic excitation power across all six configurations. Results reveal a geometric sweet spot at , where the Grooved configuration achieves the highest projected aerodynamic excitation power ( W/m), corresponding to a 2.24-fold amplification of the available fixed-body forcing relative to the smooth circular baseline and outperforming the aggressively bluff Grooved geometry. This counter-intuitive result is attributed to groove-to-boundary-layer interaction saturation: at , the shortened streamwise body dimension suppresses the shear-layer tripping mechanism. POD analysis confirms high modal coherence at the optimum, with the first two modes capturing of the total fluctuation energy, indicating forcing characteristics favourable for sustained VIV lock-in. A complementary Reynolds-number sensitivity analysis conducted at and further reveals that the groove contribution at remains uniformly suppressed relative to across the full laminar range, confirming that the saturation mechanism is a robust geometric feature rather than a Reynolds-specific artefact. However, the absolute geometric optimum is Reynolds-number dependent. delivers stronger excitation at , the two configurations converge at , and is the best-performing aspect ratio among those evaluated at , indicating the onset of the boundary-layer saturation mechanism at .