Investigating Wake Phenomena behind Triangular Bluff Body for Proposed Piezoelectric Energy Harvesting

This study investigates the influence of bluff-body length on wake dynamics for improving piezoelectric energy harvesting (PEH) in vortex-induced vibration (VIV) systems. A triangular bluff body with lengths varying from 150 mm to 10 mm is analyzed using computational fluid dynamics (CFD) simulations in ANSYS Fluent to quantify the pressure difference amplitude in the wake region, which directly governs VIV forcing and electrical output. The results show a clear increase in wake pressure fluctuations as the bluff-body length decreases, indicating stronger vortex shedding and higher excitation potential for PEH. Experimental measurements validate the CFD trends, confirming the relationship between bluff-body geometry and wake-induced pressure loading. The findings provide a design guideline for optimizing triangular bluff bodies to improve VIV-based piezoelectric power generation.