Related Experiment Video
Updated: Feb 3, 2026
09:17
Experimental Investigation of the Flow Structure over a Delta Wing Via Flow Visualization Methods
Published on: April 23, 2018
11.2K
Flow structure modifications by leading-edge tubercles on a 3D wing.
Heesu Kim1, Jooha Kim, Haecheon Choi
1Department of Mechanical & Aerospace Engineering, Seoul National University, Seoul 08826, Republic of Korea.
Bioinspiration & Biomimetics
|October 27, 2018
Summary
Humpback whale flipper tubercles enhance aerodynamic performance by delaying stall and increasing lift. These tubercles create vortical structures that manage flow separation, improving wing efficiency at various angles of attack.
Area of Science:
- Fluid Dynamics
- Bio-inspired Engineering
- Aerodynamics
Background:
- Leading-edge tubercles on humpback whale flippers improve hydrodynamic performance.
- Previous studies (Miklosovic et al., 2004) established the benefits of tubercles at post-stall angles.
- Understanding the vortical structures responsible for these benefits is crucial for aerodynamic applications.
Purpose of the Study:
- To investigate the vortical structures generated by tubercles on a 3D wing model.
- To analyze how these structures influence flow separation and stall characteristics.
- To quantify the aerodynamic performance enhancement provided by tubercles.
Main Methods:
- Surface-oil-flow visualization to observe flow patterns.
- Particle image velocimetry (PIV) to measure flow fields.
- Testing two wing models (with and without tubercles) at a Reynolds number of 180,000.
Main Results:
- Tubercles delayed stall angle by 7° and increased maximum lift by 22% at Re=180,000.
- Tubercles generated two types of vortical motions, blocking inboard flow separation.
- At post-stall angles, tubercles created streamwise vortices that delayed separation and increased lift.
Conclusions:
- Tubercles significantly enhance aerodynamic performance by delaying stall and increasing lift.
- Vortical structures generated by tubercles are key to managing flow separation.
- Bio-inspired designs incorporating tubercles offer a promising avenue for aerodynamic improvements.
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