Computational Analysis on Aerodynamics of a Boxfish-Inspired Airship

Boxfish’s unusual rigid-like shape is commonly thought as the limitation of its movement within its aquatic surroundings. Despite that, recent studies on its hydrodynamic characteristics has proved its hydrodynamic capability with some claiming that the unique boxfish shape produces less drag and helps maneuverability. These qualities are desirable for hydrodynamic and aerodynamic vehicles. Applying a biomimetic approach, this attempts to adapt the boxfish shape to airship design in order to improve its flight performance. A boxfish-shaped airship hull is designed with an approximation of the carapace shape of a yellow boxfish (Ostracion cubicus Linnaeus 1728). For aerodynamics characterization comparison, a typical ellipsoidal hull shape with a similar fineness ratio is chosen. Both airship’s hulls are analyzed using Ansys Fluent, a solver system for aerodynamic performance analysis with computational fluid dynamics approach. The drag force, lift force, yaw moment, and pitch moment is chosen as these are the qualities that relate to airship maneuverability. The results show that the boxfish-inspired airship’s hull generates better maneuverability in the yaw plane but higher drag association compared to the ellipsoid airship’s hull. Additionally, the boxfish-shaped airship’s hull promotes better stability in the pitch plane. This study demonstrates that the biomimetic airship’s hull has huge potential in the airship’s development. It is hoped that study will provide useful resources for future development of biomimetic application in lighter-than-air vehicle design.