scholarly journals Effect of angle of attack profiles in flapping foil propulsion

2004 ◽  
Vol 19 (1) ◽  
pp. 37-47 ◽  
Author(s):  
F.S. Hover ◽  
Ø. Haugsdal ◽  
M.S. Triantafyllou
Keyword(s):  
Angle Of Attack ◽  
Flapping Foil

scholarly journals Comparative investigations in the effect of angle of attack profile on hydrodynamic performance of bio-inspired foil, (corrected)

2013 ◽  
Vol 10 (2) ◽  
pp. 99-108 ◽  
Author(s):  
J. A. Esfahani ◽  
E. Barati ◽  
Hamid Reza Karbasian
Keyword(s):  
Angle Of Attack ◽  
Underwater Vehicles ◽  
Hydrodynamic Performance ◽  
Profile Function ◽  
Flapping Foil ◽  
Propulsive Performance ◽  
Wide Range ◽  
Effective Angle ◽  
Thrust Production ◽  
Optimum Profile

In flapping underwater vehicles the propulsive performance of harmonically sinusoidal heaving and pitching foil will be degraded by some awkward changes in effective angle of attack profile, as the Strouhal number increases. This paper surveys different angle of attack profiles (Sinusoidal, Square, Sawtooth and Cosine) and considers their thrust production ability. In the wide range of Strouhal numbers, thrust production of Square profile is considerable but it has a discontinuity in heave velocity profile, in which an infinite acceleration exists. This problem poses a significant defect in control of flapping foil. A novel profile function is proposed to omit sharp changes in heave velocity and acceleration. Furthermore, an optimum profile is found for different Strouhal numbers with respect to Square angle of attack profile.DOI: http://dx.doi.org/10.3329/jname.v10i2.14229

Study of the hydrodynamic of a flapping foil at moderate angle of attack

2012 ◽  
Vol 59 ◽  
pp. 117-124 ◽  
Author(s):  
O. Boiron ◽  
C. Guivier-Curien ◽  
E. Bertrand
Keyword(s):  
Angle Of Attack ◽  
Flapping Foil

scholarly journals Parametric Analysis for Underwater Flapping Foil Propulsor

Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2103
Author(s):  
Lei Mei ◽  
Junwei Zhou ◽  
Dong Yu Weichao Shi ◽  
Xiaoyun Pan ◽  
Mingyang Li
Keyword(s):  
Phase Difference ◽  
Amplitude Ratio ◽  
Angle Of Attack ◽  
Systematic Investigation ◽  
Influential Factor ◽  
Maximum Efficiency ◽  
Propulsion Efficiency ◽  
Flapping Foil ◽  
Maximum Angle ◽  
Flow Field Characteristics

This paper researched into the harmonic and anharmonic underwater flapping foil propulsion systems to improve the efficiency of these bioinspired propulsors. The angle of attack, the pitching angle, the heaving amplitude, and the phase difference are parametrically investigated in this paper. A rigid two-dimensional NACA (National Advisory Committee for Aeronautics) 0012 airfoil is modeled with the aid of a commercial computational fluid dynamics software, FINE™/Marine. Unsteady Reynolds Average Navier-Stokes (URANS) equation is solved together with dynamic mesh to simulate the foil motion. The investigation first verifies the reliability of the developed modeling method against the benchmark data. Then, the systematic investigation is conducted and identifies that the heaving amplitude is most influential factor for the propulsion efficiency. Secondly, phase difference also has a significant influence on efficiency, but this effect is related to the reference working condition, which needs further study. Then, the pitching amplitude has little effect on the maximum efficiency value of flapping foil, while it will affect its optimal speed range. When the heaving amplitude ratio reaches 3 and the corresponding maximum angle of attack is about 9°, the maximum efficiency can reach 87%. The effect of anharmonic motion on the efficiency is very small and varies with the St number, but in summary, it can maintain the peak efficiency over a wider range of operations. In addition, the force and flow field characteristics of different efficiency points are compared and analyzed to distinguish their corresponding relationship with the propulsion efficiency.

Positioning the Angle of Attack Sensor on an Unmanned Aerial Vehicle Wing

2016 ◽  
Vol 3 (1) ◽  
pp. 25-33
Author(s):  
Amir Birjandi ◽  
◽  
Valentin Guerry ◽  
Eric Bibeau ◽  
Hamidreza Bolandhemmat ◽  
...  
Keyword(s):  
Unmanned Aerial Vehicle ◽  
Angle Of Attack ◽  
Aerial Vehicle

AXISYMMETRIC BODY AT AN ANGLE OF ATTACK IN HYPERSONIC FLOW: HEAT PROBLEM

2015 ◽  
Vol 46 (2) ◽  
pp. 107-121
Author(s):  
Vyacheslav Antonovich Bashkin ◽  
Ivan Vladimirovich Egorov ◽  
Ivan Valeryevich Ezhov
Keyword(s):  
Hypersonic Flow ◽  
Angle Of Attack ◽  
Axisymmetric Body ◽  
Heat Problem ◽  
Flow Heat
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