Numerically Investigating the Energy-Harvesting Performance of an Oscillating Flat Plate with Leading and Trailing Flaps

Abstract

This study investigates the power generation capability of an oscillating wing energy harvester equipped with two actively controlled flaps positioned at the leading and trailing flaps of the wing. Various parameters, including flap lengths and pitch angles for the leading flap and trailing flap, are explored through numerical simulations. The length of the main wing body ranges from 40% to 65% of the chord length, c, while the leading and trailing flaps vary accordingly, summing up to the total length of the flat plate c = 100%. The pitch angles of the two flaps are adjusted within predefined limits. The pitch angle for the leading flap varies between 25° and 55°, while the trailing flap’s angle ranges from 10° to 40° across 298 different simulation scenarios. The results indicate that employing both leading and trailing flaps enhances the power output compared to a wing with a single flap configuration. The trailing flap deflects the incoming fluid more vertically, while the leading flap increases pressure difference across the surface of the main wing body, synergistically improving overall performance. The power output occurs at a specific length percentage: a leading flap of 30%, a main wing body of 50%, and a trailing flap of 20%, with pitch angles of 50°, 85°, and 30°, respectively, increasing the output power increments by 4.39% compared to a wing with a leading flap, 4.92% compared to a wing with a trailing flap, and 28.24% compared to a single flat plate. The highest efficiency for the specified length percentages is 40.37%.

Keywords

• energy harvester
• pitching motion
• leading flap
• oscillating flat plate
• trailing flap