Fluid–structure interaction analysis of flexible flapping wing in the Martian environment.

Flapping-wing micro air vehicle (FWMAV) is an attractive idea for Mars exploration because of its high capability in a thin atmosphere. The biggest challenge for its development is an appropriate understanding of a flapping flight with flexible wings, which is significantly complicated because flexible flapping wings can undergo large-scale deformations due to the effects of wing inertia and the aerodynamic forces exerted by the surrounding atmosphere. Fluid–structure interaction (FSI) analysis is a powerful tool for accurate investigations, but it usually has a very high computational cost, making it challenging to perform necessary parametric studies for practical designing. An efficient FSI analysis method is required. On Mars, whose atmospheric density is around 1% that of Earth, aerodynamic forces have a relatively small influence on wing deformation and may even be negligible in some cases. We thus investigate the relative contributions of the inertial force of a flapping wing and the aerodynamic forces exerted by the surrounding Martian atmosphere using a two-way coupled FSI simulation, and identify the conditions under which the aerodynamic forces are negligible. Then, we develop a computationally efficient one-way coupled FSI analysis system based on the interface-capturing method to design a flexible flapping wing for Mars exploration. Under the obtained conditions, we perform parametric studies on hovering flight with flexible flapping wings in the Martian environment with multiple aerodynamic parameters, various kinematic parameters, and material properties of the wing. We conclude that an FWMAV with a payload of around 5 g can fly for more than 1 min for the maximum density of the Martian atmosphere. • Inertial and aerodynamic force was analyzed using a two-way coupled FSI analysis. • A one-way coupled FSI analysis system was developed for efficient parametric study. • We found a design solution that can fly for more than 1 min with about 5 g payloads. [ABSTRACT FROM AUTHOR]