Model coupling biomechanics and fluid dynamics for the simulation of controlled flapping flight

Area of Science:

• Computational biomechanics
• Aerodynamics
• Bio-inspired engineering

Background:

• Simulating complex biological systems like bird flight requires integrated multiphysics approaches.
• Existing models often simplify aerodynamic interactions or lack detailed biomechanical fidelity.

Purpose of the Study:

• To develop and validate a multiphysics computational framework for bird flight simulation.
• To model the flight dynamics of a northern bald ibis (Geronticus eremita) using realistic biomechanical and aerodynamic principles.

Main Methods:

• A biomechanical model incorporating bird anatomy (bones, feathers) was coupled with an aerodynamic solver using a vortex particle-mesh method.
• An immersed lifting line represented the wing, and wing kinematics were based on biological observations.
• Closed-loop controllers were designed using a linearized model of flapping flight dynamics to achieve stable flight and speed adjustments.

Main Results:

• The framework accurately simulated bird flight, including wake dynamics, revealing limitations of the frozen-wake assumption.
• Aerodynamic forces were computed using both lifting line and control-volume methods.
• Calculated power requirements aligned with existing literature, showing expected velocity dependency.

Conclusions:

• The proposed computational framework provides a robust tool for simulating bird flight with high fidelity.
• The study highlights the importance of accurate wake representation and biomechanical details in flight dynamics.
• The developed controllers enable stable flight and maneuvering, validated through simulations of trimming and acceleration.