Aerodynamic Loads of Small-Amplitude Pitching NACA 0012 Airfoil at Reynolds Number of 1000

AIAA Journal ◽  
2018 ◽  
Vol 56 (8) ◽  
pp. 3328-3331 ◽  
Author(s):  
D. Funda Kurtulus
2019 ◽  
Vol 11 ◽  
pp. 175682931989060
Author(s):  
Dilek Funda Kurtulus

The present paper aims to investigate numerically small amplitude oscillation of NACA 0012 airfoil at Re = 1000. The airfoil is sinusoidally pitching around the quarter chord point with 1° pitch amplitude about a mean angle of attack. The computations are performed for mean angles of attack ranging from 0° to 60° and for pitching frequencies of 1 Hz and 4 Hz. The effect of the mean angle of attack and pitching frequency on the instantaneous forces as well as the vortex structure is investigated in comparison with the non-oscillatory conditions. It was shown that airfoil oscillations at the investigated conditions change the amplitude of oscillation of the aerodynamic loads. The instantaneous drag coefficient is always positive for pitching airfoil at 1 Hz. In the meantime, there are time intervals where instantaneous drag coefficient becomes negative for pitching motion at 4 Hz for mean angles of attack from 3° to 36°.


2016 ◽  
Author(s):  
Akshay Basavaraj

In regions of low wind speed, overcoming the starting torque of a Vertical Axis Wind Turbine (VAWT) becomes a challenge aspect. In order to overcome this adversity, careful selection of airfoils for the turbine blades becomes a priority. This paper tries to address the issue utilizing an approach wherein by observing the effect of merging two airfoils. Two airfoils which are of varying camber and thickness are merged and their aerodynamic characteristics are evaluated using the software XFOIL 6.96. For a variation in angle of attack from 0 to 90°, aerodynamic analysis is done in order to observe the behavior of one quarter of the entire VAWT cycle. An objective function is developed so as to observe the maximum possible torque generated by these airfoils at Reynolds number varying from 15,000–120,000. Due to change in the value of CL observed at Low Reynolds Number using commercial CFD softwares, multiple objective functions are utilized to observe the behavior over a range of Reynolds number. An experimental co-relation between the cut-in velocity and the lift-coefficient of the airfoils is developed in order to predict the cut-in velocity of the interpolated airfoils. The airfoils used for this paper are NACA 0012, NACA 0018, FX 66 S196, Clark Y (smooth), PT 40, SD 7032, A 18, SD 7080, SG 6043 and SG 6040.


2020 ◽  
Vol 1600 ◽  
pp. 012040
Author(s):  
Zhiyong Zhang ◽  
Tuantuan Wang ◽  
Yafei Wang ◽  
Hao Guo

2014 ◽  
Vol 757 ◽  
pp. 613-648 ◽  
Author(s):  
H. V. Moradi ◽  
J. M. Floryan

AbstractThe travelling wave instability in a channel with small-amplitude longitudinal grooves of arbitrary shape has been studied. The disturbance velocity field is always three-dimensional with disturbances which connect to the two-dimensional waves in the limit of zero groove amplitude playing the critical role. The presence of grooves destabilizes the flow if the groove wavenumber $\def \xmlpi #1{}\def \mathsfbi #1{\boldsymbol {\mathsf {#1}}}\let \le =\leqslant \let \leq =\leqslant \let \ge =\geqslant \let \geq =\geqslant \def \Pr {\mathit {Pr}}\def \Fr {\mathit {Fr}}\def \Rey {\mathit {Re}}\beta $ is larger than $\beta _{tran}\approx 4.22$, but stabilizes the flow for smaller $\beta $. It has been found that $\beta _{tran}$ does not depend on the groove amplitude. The dependence of the critical Reynolds number on the groove amplitude and wavenumber has been determined. Special attention has been paid to the drag-reducing long-wavelength grooves, including the optimal grooves. It has been demonstrated that such grooves slightly increase the critical Reynolds number, i.e. such grooves do not cause an early breakdown into turbulence.


Author(s):  
Vani Sadadiwala

This work reflects the study and detailed analysis of NACA 0012 airfoil at different angles of attack with a constant value of Reynolds Number. The geometrical designing of the airfoil is done using FreeCad and the computational analysis is carried out using Simflow 4.0- OpenFoam Interface. The analysis is fully based upon the concepts of FEM and CFD. The velocity is kept constant with various angles of attack. CFD methods are reliable source of analysis and hence can be replaced with the experimental wind tunnel methods. Boundary layer approaches were taken into consideration using the meshing techniques. The main purpose of this work is to study the symmetric profile of NACA 0012 with varying angles and the behaviour of 0012 at specific conditions. At the end, various graphs are plotted depicting the relationship of Angle of Attack with other dimensionless quantities.


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