Power extraction efficiency improvement of a fully-activated flapping foil: With the help of an auxiliary rotating foil

2015 ◽  
Vol 57 ◽  
pp. 219-228 ◽  
Author(s):  
J. Wu ◽  
J.P. Zhan ◽  
X. Wang ◽  
N. Zhao
Keyword(s):  
Extraction Efficiency ◽  
Efficiency Improvement ◽  
Power Extraction ◽  
Flapping Foil

Use of synthetic jet to a fully-active flapping foil for power extraction enhancement

2020 ◽  
pp. 095440622091522
Author(s):  
Yadong Li ◽  
Guoqing Zhou ◽  
Jie Wu
Keyword(s):  
Vortex Shedding ◽  
Extraction Efficiency ◽  
Synthetic Jet ◽  
Synthetic Jets ◽  
Foil Surface ◽  
Power Extraction ◽  
Flapping Foil ◽  
Extraction Performance ◽  
Rotational Motions ◽  
Inclined Angle

The power extraction performance of a fully-active flapping foil with synthetic jet is numerically investigated in this work. An elliptic airfoil with ratio of 8, which is placed in a two-dimensional laminar flow, is adopted to extract power from the flow. The foil implements the imposed translational and rotational motions synchronously. A pair of synthetic jets with the same frequency and strength is integrated into the upper and lower surfaces of flapping foil. As a result, the flow field around the foil could be affected by the synthetic jets greatly. At the Reynolds number of 1000 and the pitching axis location of half chord, the effects of the jet strength, the inclined angle between the jet direction and the chord line, as well as the phase angle between the synthetic jets and the flapping motion on the power extraction performance are systematically investigated. Compared with the traditional flapping foil, it is demonstrated that the enhancement of power extraction efficiency can be achieved with the help of synthetic jets. Based on the numerical analysis, it is indicated that the jet flow on the foil surfaces alters the vortex-shedding process and modifies the pressure distribution on the foil surface. As a result, the overall power extraction of the flapping foil can be benefitted.

scholarly journals A Model for Performance Estimation of Flapping Foil Operating as Biomimetic Stream Energy Device

2020 ◽  
Vol 9 (1) ◽  
pp. 21
Author(s):  
Iro E. Malefaki ◽  
Kostas A. Belibassakis
Keyword(s):  
Vertical Axis ◽  
Flow Speed ◽  
Performance Estimation ◽  
Speed Ratio ◽  
Power Extraction ◽  
Flapping Foil ◽  
Flow Energy ◽  
Novel Concept ◽  
Angular Oscillations ◽  
Energy Converters

During the recent period intensive research has focused on the advancement of engineering and technology aspects concerning the development and optimization of wave and current energy converters driven by the need to increase the percentage of marine renewable sources in the energy-production mix, particularly from offshore installations. Most stream energy-harvesting devices are based on hydro-turbines, and their performance is dependent on the ratio of the blade-tip speed to incident-flow speed. As the oncoming speed of natural-occurring currents varies randomly, there is a penalty for the latter device’s performance when operating at non-constant tip-speed ratio away from the design value. Unlike conventional turbines that are characterized by a single degree of freedom rotating around an axis, a novel concept is examined concerning hydrokinetic energy converters based on oscillating hydrofoils. The biomimetic device includes a rotating, vertically mounted, biomimetic wing, supported by an arm linked at a pivot point on the mid-chord. Activated by a controllable self-pitching motion the system performs angular oscillations around the vertical axis in incoming flow. In this work, the performance of the above flapping-foil, biomimetic flow energy harvester is investigated by application of a semi-3D model based on unsteady hydrofoil theory and the results are verified by comparison to experimental data and a 3D boundary element method based on vortex rings. By systematical application of the model the power extraction and efficiency of the system is presented for various cases including different geometric, mechanical, and kinematic parameters, and the optimal performance of the system is determined.

scholarly journals An improved P&O MPPT control algorithm for increasing power extraction efficiency of solar PV module

2019 ◽  
Vol 623 ◽  
pp. 012020
Author(s):  
D Dinesh Kumar ◽  
Challa Babu ◽  
K Jyotheeswara Reddy ◽  
K Kumar ◽  
N K Kumar
Keyword(s):  
Control Algorithm ◽  
Extraction Efficiency ◽  
Solar Pv ◽  
Power Extraction ◽  
Pv Module

Study on Performance Enhancement of a Flapping Foil Energy Harvester Using Circulation Control

2021 ◽  
Vol 143 (7) ◽  
Author(s):  
Fangrui Shi ◽  
Xiaojing Sun
Keyword(s):  
Extraction Efficiency ◽  
Performance Enhancement ◽  
Net Energy ◽  
Circulation Control ◽  
Energy Extraction ◽  
Injection Port ◽  
Flapping Foil ◽  
Momentum Coefficient ◽  
Reduced Frequency ◽  
Wide Range

Abstract Oscillating motion, an effective way to harvest energy, has gradually become a hotspot in bionic motion research in recent years. Means of improving the energy-extraction efficiency of a flapping foil harvester have long been a focus of researchers. This paper proposes a new flapping foil harvester with circulation control and explores the effects of different parameters on its energy-extraction capacity to improve efficiency and achieve lowest cost. Setting the injection ports on the upper and lower surfaces near the trailing edge of the foil and implementing injection control during motion, the effects of the location of the injection port, pitching amplitude, momentum coefficient, reduced frequency, and jet mode on the circulation control flapping foil are systematically investigated under the condition of a Reynolds number of 13,800. The results show that circulation control can enhance the energy-extraction efficiency of a flapping foil across a wide range of parameters, in which the location of the injection port and momentum coefficient have the most obvious influence on efficiency, followed by pitching amplitude and reduced frequency. In addition, the jet mode is a crucial factor affecting net efficiency. Relative to the constant mode, the triangular mode of circulation control has the lowest energy consumption, and the net energy-extraction efficiency reaches up to 38.77% under a reduced frequency of 0.12, which is 22.24% higher than that of the plain flapping foil.

Inertial effects of the semi-passive flapping foil on its energy extraction efficiency

2015 ◽  
Vol 27 (5) ◽  
pp. 053103 ◽  
Author(s):  
Jian Deng ◽  
Lubao Teng ◽  
Dingyi Pan ◽  
Xueming Shao
Keyword(s):  
Extraction Efficiency ◽  
Energy Extraction ◽  
Inertial Effects ◽  
Flapping Foil
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