An Empirical Study of Grid Fins Aerodynamic Performance in Low-Subsonic Flight

Abstract

Deploying payloads from aerial platforms at low altitudes poses significant challenges, particularly in maintaining an accurate freefall trajectory. Traditional fin designs are often used in dropped payloads at low altitudes. However, these designs frequently fail to preserve the intended trajectory, reducing precision and effectiveness. This challenge is particularly evident in high-wind conditions, where achieving landing precision or maintaining a desired trajectory becomes more difficult. To address these limitations, alternative fin designs, such as grid fins, offer a promising solution due to their unique aerodynamic properties. The current study investigates the aerodynamic performance of grid fins in low-subsonic flight, focusing on their application in drone-dropped payloads. The primary objective is to assess how different grid fin design parameters affect aerodynamic performance. Experimental analyses are conducted through subsonic wind tunnel testing of various grid fin designs. The study highlights the differences in aerodynamic performance resulting from grid count variations and the grid members' horizontal versus diagonal placement. The experimental results indicate that grid fins with a diagonal configuration outperform their horizontal counterparts with the same grid numbers and dimensions. The findings reveal the presence of an optimal configuration, achieving a peak lift-to-drag (L/D) ratio of approximately 1.99, compared to 1.4 for the least optimal design.