A modified blade element theory for estimation of forces generated by a beetle-mimicking flapping wing system

Area of Science:

• Aerodynamics
• Bio-inspired engineering
• Fluid mechanics

Background:

• Estimating aerodynamic forces in flapping flight is complex.
• Existing models may not fully capture unsteady aerodynamic phenomena.
• Beetle flight offers insights into efficient aerial locomotion.

Purpose of the Study:

• To develop and validate an unsteady blade element theory (BET) model for estimating aerodynamic forces.
• To apply the model to both freely flying beetles and beetle-mimicking flapping wing systems.
• To incorporate unsteady forces like added mass and rotational effects.

Main Methods:

• Developed an unsteady blade element theory (BET) model.
• Included added mass and rotational forces for unsteady effects.
• Calculated inertial forces based on full 3D wing motion.
• Validated the model against existing experimental data (5.7% average difference).
• Captured wing kinematics using high-speed cameras for real beetles and artificial systems.

Main Results:

• The validated BET model accurately estimates aerodynamic forces.
• Estimated vertical force for a real beetle closely matches its weight.
• Estimated thrust for a beetle-mimicking system agrees well with measured values.
• Demonstrated the utility of unsteady lift and drag coefficients for higher Reynolds numbers.

Conclusions:

• The proposed unsteady BET model is effective for estimating forces in flapping wing systems.
• The model provides a reliable method for analyzing bio-inspired flight.
• Unsteady aerodynamic principles are crucial for understanding insect flight dynamics.