Piezoelectric is a tool that can harvest energy in the form of electricity when it is deflected, and can also experience changes in dimensions due to changes in pressure or tensile forces experienced by the piezoelectric (Gamayel. 2019). However, the small and thin dimensions of the piezoelectric cause the small deflection produced by the piezoelectric, which is the weakness of the piezoelectric. Therefore, piezoelectric is classified as a producer of electrical energy for the micro level. The purpose of this study was to determine the potential for electrical energy generated in piezoelectric energy harvesters based on the fluid flow pattern that passes through the rhombus body bluff barrier with three size variations of 5 cm. 7 cm, and 9 cm. The independent variables in this study were variations in the size of the rhombus bluff body, and variations in wind speed, namely 5 m/s, 7 m/s, and 9 m/s. Where the variation of the rhombus bluff body with different sizes, the study was carried out in a wind tunnel and the cross-sectional distance of the bluff body to the piezoelectric is 80 cm. The results of the variable cross-sectional size of the rhombus bluff body which produces the highest electrical voltage, namely the rhombus bluff body cross-section with a size of 7 cm, with a variable speed that produces the highest electrical voltage, which is at a speed of 9 m/s producing an electric voltage of 5.58 volts with a cross sectional bluff body rhombus size 7 cm. Based on this research, in the presence of turbulence caused by flowing fluid, the fins move up and down to strike the piezoelectric. The greater the air flow and oscillation, then the movement of the fins up and down will be even greater. This is evidenced by the large voltage generated by the piezoelectric.

Keywords: Piezoelectric, Electric energy harvester, bluff body