Numerical study of flexible wing aerodynamic characteristics of bionic flapping-wing vehicle in Martian atmosphere

Aiming at the aerodynamic design problem of the bionic flapping wing vehicle in the low-density atmosphere of Mars, this paper proposes a flexible wing aerodynamic characteristics analysis framework based on fluid-structure interaction method. A three-dimensional flapping wing kinematics model integrating active actuation and passive deformation is established. Combined with the modified SST k-ω turbulence model and Ogden’s hyperelastic constitutive relation, the bi-directional coupled numerical simulation of low Reynolds number CO 2 flow (Re≈ 10 3 - 10 4 ) and nonlinear deformation of the flexible wing is realized. The results show that the spanwise stiffness exponential gradient distribution (attenuation coefficient γ = 1.8) can increase the time-average lift coefficient by 21.3% by regulating the cyclic migration. The parameter combination of flapping frequency of 12 Hz, amplitude of 45°, and phase difference of 75° can optimize the vortex interaction, and the lift-to-push ratio reaches 2.8 (26.3% higher than the reference condition). The lift attenuation rate of the flexible wing in the Martian dust environment (18%) is significantly lower than that of the rigid wing (43%), which verifies its environmental adaptability advantage. The research results provide a stiffness gradient regulation criterion and a motion parameter optimization method for the design of Mars bionic spacecraft and reveal the physical mechanism of the flexible deformation to enhance the aerodynamic performance at low Reynolds number. Future research needs to further solve the engineering application problems such as material performance degradation under extreme temperatures and wear resistance of the driving mechanism.