Related Experiment Video
Updated: Aug 28, 2025
09:17
Experimental Investigation of the Flow Structure over a Delta Wing Via Flow Visualization Methods
Published on: April 23, 2018
10.8K
The Aerodynamic Effect of an Alula-like Vortex Generator on a Revolving Wing
Ping-Han Chung1, Po-Hsiang Chang1, Szu-I Yeh1
1Department of Aeronautics and Astronautics Engineering, National Cheng Kung University, Tainan 701, Taiwan.
Biomimetics (Basel, Switzerland)
|September 22, 2022
Summary
An alula-like vortex generator (alula-VG) improves revolving wing aerodynamics by influencing leading-edge vortex (LEV) behavior. Its effectiveness depends on placement and angle of attack for optimal flow control.
Area of Science:
- Aerodynamics
- Fluid Mechanics
- Bio-inspired Engineering
Background:
- The alula, a bird feather structure, prevents stalling by manipulating airflow.
- Understanding bio-inspired mechanisms for aerodynamic control is crucial for aircraft design.
- Revolving wings present unique aerodynamic challenges, especially near stall conditions.
Purpose of the Study:
- To investigate the aerodynamic effects of an alula-like vortex generator (alula-VG) on a revolving wing model.
- To analyze how the alula-VG influences leading-edge vortex (LEV) dynamics and overall wing performance.
- To determine the optimal placement and angle of attack for alula-VG effectiveness on revolving wings.
Main Methods:
- Particle Image Velocimetry (PIV) was employed in a water tank to visualize flow fields.
- A rectangular wing model with and without an alula-VG was subjected to revolving motion at various angles of attack.
- Analysis included vorticity contours, vortex circulation, and sectional lift coefficients.
Main Results:
- The alula-VG significantly impacts the lift-off and bursting of the leading-edge vortex (LEV).
- Flow interactions involving alula-VG induced spanwise flow, inertial forces, and wing-tip vortices are key to vortex bursting.
- Aerodynamic performance enhancement by the alula-VG is contingent upon its spanwise position and the wing's angle of attack.
Conclusions:
- Alula-VGs can modify vortex dynamics to improve revolving wing performance.
- The interaction between the alula-VG, revolving motion, and wing-tip vortex is critical for aerodynamic outcomes.
- Proper matching of alula-VG spanwise position and wing angle of attack is essential for maximizing benefits.
Related Concept Videos
01:23Lift
220
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...
220
01:09Moment-of-Momentum Equation
178
The moment-of-momentum equation is a critical tool for analyzing the torque produced by the rotating blades of a wind turbine. This equation is derived by applying Newton's second law to a fluid particle, which states that the rate of change of linear momentum is equal to the external force acting on the particle.
178
01:25Electric Generator: Alternator
2.6K
Electric generators induce an emf by rotating a coil in a magnetic field. A simple alternator is an AC generator that creates electrical energy that varies sinusoidally with time. A simple alternator consists of a conducting loop that is placed inside a uniform magnetic field. The loop is connected to split rings connected to the external circuit with the help of brushes.
The magnetic flux passing through the coil varies sinusoidally as the loop rotates inside the magnetic field. This...
The magnetic flux passing through the coil varies sinusoidally as the loop rotates inside the magnetic field. This...
2.6K
01:23Steady, Laminar Flow in Circular Tubes
326
Hagen-Poiseuille flow describes a viscous fluid's steady, incompressible flow through a cylindrical tube with a constant radius R. This flow profile is often applied to understand fluid transport in narrow channels, such as capillaries. It serves as a foundational example of laminar flow. In this model, cylindrical coordinates (r,θ,z) are used to describe the radial (r), angular (θ), and axial (z) dimensions within the tube. For Hagen-Poiseuille flow, the velocity profile is...
326
01:01Bernoulli's Principle
10.2K
Bernoulli's equation incorporates how fluid pressure changes across a static, incompressible fluid by equating the kinetic energy contribution to zero. It is also helpful in analyzing horizontal flows in which the gravitational energy density is constant throughout. The latter equation is so useful that it is called Bernoulli's principle. According to Bernoulli's principle, the fluid pressure drops if the speed increases and vice versa.
Bernoulli's principle has several...
Bernoulli's principle has several...
10.2K
01:16Bernoulli's Equation for Flow Normal to a Streamline
935
Bernoulli's equation for flow normal to a streamline explains how pressure varies across curved streamlines due to the outward centrifugal forces induced by the fluid's curvature. The pressure is higher on the inner side of the curve, near the center of curvature, and decreases outward to balance these centrifugal forces.
The pressure difference depends on the fluid's velocity and radius of curvature. The pressure variation is minimal in flows with nearly straight streamlines.
The pressure difference depends on the fluid's velocity and radius of curvature. The pressure variation is minimal in flows with nearly straight streamlines.
935