On the Wake Properties of Segmented Trailing Edge Extensions
1.1. Vortex Mitigation Techniques
2. Experimental Setup
2.1. Wind Tunnel
2.2. Test Model
2.3. Force Based Experiment
2.4. Force Transducer
2.5. Particle Image Velocimetry (PIV) Setup
3. Influence of Reynolds Number
4.1. Force-Based Experimental Results
4.2. Momentum Deficit
4.4. Coherent Structures
4.5. Reynolds Stress
4.6. Root-Mean Square (RMS) Velocities
- The TE extensions had a minor effect on the coefficient of lift but had measurable impact on the coefficient of drag at high angles of attack. With the segmented TE extensions, the total drag coefficient reduced by 8% at an 8° angle of attack.
- Evidence for the cause of reduction in parasitic drag with TE extensions was supported by mean flow quantities, such as mean velocity and normalized vorticity. Both parameters showed measurable and significant reductions when compared to the baseline, especially in the vorticity case. The average reduction in vorticity is in the order of 40% at an 8° angle of attack.
- The reduction in vorticity behind TE extensions was further supported by determining the coherent structures in the wake. A comparatively lower correlation of the wake and the upper surface shear layer indicates lower velocity and pressure fluctuations behind the TE extensions when compared to the baseline.
- The lower pressure fluctuations can be supported by the changes observed in the Reynolds stress. On average, the magnitude of the Reynolds stress was reduced by 40% on the upper surface and by 55% on the lower surface.
- The reduction in fluctuations are further validated by determining and , which showed an average decrease in magnitude of 15% and 57%, respectively.
Conflicts of Interest
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|Test Model||Reynolds Number||Angle of Attack (Degrees)|
|AR 4 NACA 0012 without TE Extensions||200,000||−15 to 15|
|AR 4 NACA 0012 with TE Extensions||200,000||−15 to 15|
|Test Model||Angle of Attack (Degrees)||Interrogation Location|
|AR 4 NACA 0012 without TE Extensions||0, 2, 4, 6, 8||Behind TE|
|AR 4 NACA 0012 with TE Extensions||0, 2, 4, 6, 8||Behind TE Extension|
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Gunasekaran, S.; Curry, D. On the Wake Properties of Segmented Trailing Edge Extensions. Aerospace 2018, 5, 89. https://doi.org/10.3390/aerospace5030089
Gunasekaran S, Curry D. On the Wake Properties of Segmented Trailing Edge Extensions. Aerospace. 2018; 5(3):89. https://doi.org/10.3390/aerospace5030089Chicago/Turabian Style
Gunasekaran, Sidaard, and Daniel Curry. 2018. "On the Wake Properties of Segmented Trailing Edge Extensions" Aerospace 5, no. 3: 89. https://doi.org/10.3390/aerospace5030089