On the wake flow of asymmetrically beveled trailing edges

Guan, Yaoyi; Pröbsting, Stefan; Stephens, David B.; Gupta, Abhineet; Morris, Scott

doi:10.1007/s00348-016-2172-2

“…The vortex shedding is also a function of trailing edge geometry. Guan et al [7] experimented with multiple beveled trailing edge geometries and showed that even subtle changes in geometry can result in substantial changes in wake signatures. The vortex shedding is greater at the sharp trailing edge when compared to the smooth trailing edges.…”

Section: Wing Wakementioning

confidence: 99%

Effect of Piezo-Embedded Inverted Flag in Free Shear Layer Wake

Gunasekaran

¹

,

Ross

²

2019

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The use of flexible inverted piezo embedded Polyvinylidene Difluoride (PVDF) as a simultaneous energy harvester and as a wake sensor is explored. The oscillation amplitude (characterized by voltage output) and oscillation frequency of the piezo-embedded PDVF was quantified in the wake of a 2D NACA 0012 model and SD7003 model at a Reynolds number of 100,000 and 67,000, respectively. The performance of the sensor was also quantified in the freestream without the presence of the wing. In order to quantify the sensor response to angle of attack and downstream distance, the amplitude and frequency of oscillations were recorded in the wing wake. Increase in angle of attack of the wing resulted in increase in oscillation frequency and amplitude of the PVDF. The results also indicated that the inverted flag configuration performed better in the wake under unsteady conditions when compared to freestream conditions. The results from Particle Image Velocimetry indicated that the wake signature was not affected by the presence of the PVDF in the wake. The root mean square voltage contours in the wake of SD7003 airfoil show remarkable free shear layer wake features such as upper and lower surface stratification and downwash angle which shows the sensitivity of the sensor to the unsteadiness in the wake. The capability of this device to act as a potential energy harvester and as a sensor has serious implications in extending the mission capabilities of small UAVs.

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“…The vortex shedding is also found to be a function of trailing edge geometry. Guan et al [6] experimented with multiple beveled trailing edge geometries and showed that even subtle changes in geometry can result in substantial changes in wake signatures. The vortex shedding was found to be greater at the sharp trailing edge when compared to the smooth trailing edges.…”

Section: Introductionmentioning

confidence: 99%

On the Wake Properties of Segmented Trailing Edge Extensions

Gunasekaran¹,

Curry²

2018

Preprint

0

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Changes in the amount and the distribution of mean and turbulent quantities in the free shear layer wake of a 2D NACA 0012 airfoil and AR 4 NACA 0012 wing with passive segmented rigid trailing edge (TE) extensions was investigated at the University of Dayton Low Speed Wind Tunnel (UD-LSWT). The TE extensions were intentionally placed at zero degrees with respect to the chord line to study the effects of segmented extensions without changing the effective angle of attack. Force based experiments was used to determine the total lift coefficient variation of hte wing with seven segmented trailing edge extensions distributed across the span. The segmented trailing edge extensions had negligible effect of lift coefficient but showed measurable decrement in sectional and total drag coefficient. Investigation of turbulent quantities (obtained through Particle Image Velocimetry (PIV)) such as Reynolds stress, streamwise and transverse RMS in the wake, reveal a significant decrease in magnitude when compared to the baseline. The decrease in the magnitude of turbulent parameters was supported by the changes in coherent structures obtained through two-point correlations. Apart from the reduction in drag, the lower turbulent wake generated by the extensions has implications in reducing structural vibrations and acoustic tones.

show abstract

“…The vortex shedding is also found to be a function of trailing edge geometry. Guan et al [6] experimented with multiple beveled trailing edge geometries and showed that even subtle changes in geometry can result in substantial changes in wake signatures. The vortex shedding was found to be greater at the sharp trailing edge when compared to the rounded trailing edges.…”

Section: Introductionmentioning

confidence: 99%

On the Wake Properties of Segmented Trailing Edge Extensions

Gunasekaran¹,

Curry²

2018

Preprint

1

0

View full text Add to dashboard Cite

Changes in the amount and the distribution of mean and turbulent quantities in the free shear layer wake of a 2D NACA 0012 airfoil and AR 4 NACA 0012 wing with passive segmented rigid trailing edge (TE) extensions was investigated at the University of Dayton Low Speed Wind Tunnel (UD-LSWT). The TE extensions were intentionally placed at zero degrees with respect to the chord line to study the effects of segmented extensions without changing the effective angle of attack. Force based experiments was used to determine the total lift coefficient variation of hte wing with seven segmented trailing edge extensions distributed across the span. The segmented trailing edge extensions had negligible effect of lift coefficient but showed measurable decrement in sectional and total drag coefficient. Investigation of turbulent quantities (obtained through Particle Image Velocimetry (PIV)) such as Reynolds stress, streamwise and transverse RMS in the wake, reveal a significant decrease in magnitude when compared to the baseline. The decrease in the magnitude of turbulent parameters was supported by the changes in coherent structures obtained through two-point correlations. Apart from the reduction in drag, the lower turbulent wake generated by the extensions has implications in reducing structural vibrations and acoustic tones.

show abstract

On the wake flow of asymmetrically beveled trailing edges

Abstract: On the wake flow of asymmetrically beveled trailing edges. Experiments in Fluids: experimental methods and their applications to fluid flow, 57(5), [78].

Cited by 17 publications

References 30 publications

Effect of Piezo-Embedded Inverted Flag in Free Shear Layer Wake

Effect of Piezo-Embedded Inverted Flag in Free Shear Layer Wake

On the Wake Properties of Segmented Trailing Edge Extensions

On the Wake Properties of Segmented Trailing Edge Extensions

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