Related Experiment Video
Updated: May 30, 2026
09:17
Experimental Investigation of the Flow Structure over a Delta Wing Via Flow Visualization Methods
Published on: April 23, 2018
Effect of outer wing separation on lift and thrust generation in a flapping wing system
Nanang Mahardika1, Nguyen Quoc Viet, Hoon Cheol Park
1Department of Advanced Technology Fusion, Konkuk University, Seoul, Korea.
Bioinspiration & Biomimetics
|August 20, 2011
Summary
This study introduces a biomimetic flapping wing with separated outer wings, enhancing thrust and lift. The separated wing design improves forward force generation and reduces downward force compared to traditional closed wings.
Area of Science:
- Aerospace Engineering
- Biomimetics
- Fluid Dynamics
Background:
- Flapping wing systems mimic natural flight for enhanced maneuverability and efficiency.
- Traditional flapping wings face limitations in optimizing aerodynamic performance.
- Wing feather separation is a novel approach to improve aerodynamic efficiency.
Purpose of the Study:
- To design and demonstrate a biomimetic flapping wing system with separated outer wings.
- To evaluate the impact of wing feather separation and lead-lagging motion on aerodynamic performance.
- To compare the propulsive and lift forces of separated versus closed outer wings.
Main Methods:
- A biomimetic flapping wing system was designed with artificial wing feather separation.
- High-speed videography was used to capture flapping, lead-lagging, and wing separation dynamics.
- Experimental comparisons were made between separated and closed outer wing configurations.
Main Results:
- The separated wing system demonstrated higher thrust and lift generation capabilities at low flapping frequencies (2.47–3.90 Hz).
- Compared to closed wings, separated wings produced approximately 56% more forward force and 61% less downward force at 1.6 V.
- Outer wing sections deformed during the upstroke, reducing drag while maintaining lift and thrust during the downstroke.
Conclusions:
- Wing feather separation in flapping wing systems significantly enhances aerodynamic performance.
- The biomimetic design with separated outer wings offers improved thrust and lift generation.
- This approach shows potential for developing more efficient bio-inspired flying devices.
Related Concept Videos
01:23Lift
Lift is a fundamental aerodynamic force that acts perpendicular to the direction of airflow. It plays a central role in achieving and sustaining flight and in stabilizing various vehicles. Lift primarily originates from pressure differences created across surfaces, such as an airfoil. A lower pressure region forms above the wing, while a higher pressure region forms below it, generating an upward force. This differential results from the shape and orientation of the airfoil, enabling the wing...
01:26General External Flow Characteristics
The study of external flow is essential for creating structures and objects that interact efficiently and safely with moving fluids, such as air or water. When a body is immersed in a flowing fluid, it experiences two primary forces: drag, which opposes motion along the flow direction, and lift, which acts perpendicular to the flow. The shape, size, and orientation of the object influence these forces.Streamlined and Blunt Bodies in External FlowObjects in fluid flow are classified as...
01:15Determination of Pi Terms
The Buckingham Pi theorem is a valuable method in dimensional analysis, reducing complex relationships between variables into dimensionless terms. Relevant variables in analyzing the lift force on an airplane wing include lift force, air density, wing area, aircraft velocity, and air viscosity. Expressing each variable in terms of fundamental dimensions — mass, length, and time — provides a consistent foundation for constructing these dimensionless terms.
The theorem indicates that the number...
The theorem indicates that the number...
01:18Boundary Layer Characteristics
When a fluid encounters a solid surface, a boundary layer forms due to the interaction between the fluid's motion and the stationary surface. This phenomenon is characterized by a thin region adjacent to the surface where viscous forces dominate, influencing the fluid's velocity profile. The development of the boundary layer begins at the leading edge of the surface and evolves as the fluid moves downstream.As the fluid flows over the surface, friction between the fluid and the wall slows down...
01:23Drag
Drag is a resistive force opposing an object’s motion through a fluid, resulting from surface pressure and shear forces. It comprises two components: a perpendicular one from pressure and a tangential one from shear stress. Accurate drag calculations use pressure and wall shear stress distributions, often determined through Computational Fluid Dynamics (CFD) or wind tunnel testing. The drag coefficient, a dimensionless measure, depends on factors like shape, Reynolds number, Mach number, Froude...
01:05Static and Kinetic Frictional Force
One of the simpler characteristics of sliding friction is that it is parallel to the contact surfaces between systems, and is always in a direction that opposes the motion or attempted motion of the systems relative to each other. If two systems are in contact and moving relative to one another, then the friction between them is called kinetic friction. For example, kinetic friction slows a hockey puck sliding on ice.
However, if two systems are in contact and are stationary relative to one...
However, if two systems are in contact and are stationary relative to one...