Energy extraction of oscillating foil with an active deflecting trailing-edge flap

2021 ◽  
Vol 13 (6) ◽  
pp. 064501
Author(s):  
Gang Liu ◽  
Chenye Tian ◽  
Liming Wu ◽  
Xiaomin Liu
Keyword(s):  
Energy Extraction ◽  
Trailing Edge ◽  
Trailing Edge Flap ◽  
Oscillating Foil

Hydrodynamic and energy extraction properties of oscillating hydrofoils with a trailing edge flap

2021 ◽  
pp. 102530
Author(s):  
Guang Sun ◽  
Yong Wang ◽  
Yudong Xie ◽  
Penglei Ma ◽  
Yubing Zhang
Keyword(s):  
Energy Extraction ◽  
Trailing Edge ◽  
Extraction Properties ◽  
Trailing Edge Flap

Performance enhancement evaluation of an actuated trailing edge flap

2001 ◽  
Vol 105 (1049) ◽  
pp. 391-399 ◽  
Author(s):  
W. Chan ◽  
A. Brocklehurst
Keyword(s):  
Adverse Effect ◽  
Performance Enhancement ◽  
Optimal Configuration ◽  
Analytical Evaluation ◽  
Trailing Edge ◽  
Design Constraints ◽  
Flight Condition ◽  
Trailing Edge Flap

Abstract An analytical evaluation of the performance enhancement due to a servo-actuated trailing edge flap was carried out using the coupled rotor-fuselage model (CRFM). The performance enhancement from a trailing edge flap is achieved by introducing effective camber around the azimuth for a nominal aerofoil. An investigation on the best combination of flap parameters, namely the span, position, chord and deflection was carried out in order to identify an optimal configuration within given design constraints. The effects on vibratory control loads over a range of speed for a flap of 10% span, 20% chord, actuated at once per rev has expanded the retreating blade envelope for a Lynx aircraft by some 20kt. The flap hinge load was also examined and it was found not to be excessive. It was also confirmed that an actuated trailing edge flap does not have adverse effect on the pilot's control inputs to trim to a particular flight condition. This paper will discuss the aerodynamic enhancements derived from the application of the trailing edge flap and present conclusions drawn from this study.

scholarly journals Active vorticity control in a shear flow using a flapping foil

1994 ◽  
Vol 274 ◽  
pp. 1-21 ◽  
Author(s):  
R. Gopalkrishnan ◽  
M. S. Triantafyllou ◽  
G. S. Triantafyllou ◽  
D. Barrett
Keyword(s):  
Reynolds Number ◽  
Vortex Formation ◽  
Interaction Patterns ◽  
Energy Extraction ◽  
Stable Pattern ◽  
Torque Measurements ◽  
Reverse Circulation ◽  
Visualization Experiments ◽  
Oscillating Foil ◽  
The Impact

It is shown experimentally that free shear flows can be substantially altered through direct control of the large coherent vortices present in the flow.First, flow-visualization experiments are conducted in Kalliroscope fluid at Reynolds number 550. A foil is placed in the wake of a D-section cylinder, sufficiently far behind the cylinder so that it does not interfere with the vortex formation process. The foil performs a heaving and pitching oscillation at a frequency close to the Strouhal frequency of the cylinder, while cylinder and foil also move forward at constant speed. By varying the phase of the foil oscillation, three basic interaction modes are identified. (i) Formation of a street of pairs of counter-rotating vortices, each pair consisting of one vortex from the initial street of the cylinder and one vortex shed by the foil. The width of the wake is then substantially increased. (ii) Formation of a street of vortices with reduced or even reverse circulation compared to that of oncoming cylinder vortices, through repositioning of cylinder vortices by the foil and interaction with vorticity of the opposite sign shed from the trailing edge of the foil. (iii) Formation of a street of vortices with circulation increased through merging of cylinder vortices with vortices of the same sign shed by the foil. In modes (ii) and (iii) considerable repositioning of the cylinder vortices takes place immediately behind the foil, resulting in a regular or reverse Kármán street. The formation of these three interaction patterns is achieved only for specific parametric values; for different values of the parameters no dominant stable pattern emerges.Subsequently, the experiments are repeated in a different facility at larger scale, resulting in Reynolds number 20000, in order to obtain force and torque measurements. The purpose of the second set of experiments is to assess the impact of flow control on the efficiency of the oscillating foil, and hence investigate the possibility of energy extraction. It is found that the efficiency of the foil depends strongly on the phase difference between the oscillation of the foil and the arrival of cylinder vortices. Peaks in foil efficiency are associated with the formation of a street of weakened vortices and energy extraction by the foil from the vortices of the vortex street.

Effect of shroud on the energy extraction performance of oscillating foil

Energy ◽  
2021 ◽  
pp. 122387
Author(s):  
W. Jiang ◽  
Z.Y. Mei ◽  
F. Wu ◽  
A. Han ◽  
Y.H. Xie ◽  
...  
Keyword(s):  
Energy Extraction ◽  
Extraction Performance ◽  
Oscillating Foil
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