Numerical and experimental investigation of pitching / plunging airfoils in hover

Download
index.pdf
2012
Hızlı, Hasan
Show full item record
224
views
106
downloads
In this thesis, results of the numerical and experimental study corresponding to four airfoils, namely SD7003, NACA0012, 10% thick elliptical, 10% thick flat plate, undergoing sinusoidal pure pitch, pure plunge and combined pitch-plunge types of hovering motion are presented. A number of cases are investigated consisting of different pitching and plunging amplitudes. The study aims to provide a better understanding of the aerodynamics phenomena and the vortex topology of flapping wings in motion for application to micro air vehicle (MAV) designs, to investigate the effect of pitching and plunging amplitudes on the different modes of hovering motion and to compare the numerical and experimental results for validation of the newly built experimental setup with the numerical simulations by means of the instantaneous flow topologies. The unsteady, incompressible Navier-Stokes equations are solved for the extensive numerical simulation of the flow field around the airfoils whereas the instantaneous velocity field data of the flow are acquired by the Particle Image Velocimetry (PIV) measurements. An agreement between the numerical and experimental results of the investigated test cases is observed in terms of the instantaneous vortex structure of the flow. Among the studied cases, the highest mean lift coefficient is obtained from pitching-plunging (αa=30o, xa=0.01 m) SD7003 airfoil while the lowest is obtained from purely plunging (xa=0.02 m) 10% thick flat plate airfoil. Moreover, pitching-plunging (αa=30o, xa=0.02 m) SD7003 airfoil gives the lowest mean drag coefficient whereas pitching-plunging (αa=45o, xa=0.01 m) 10% thick elliptical airfoil gives the highest.
Flaps (Airplanes)., Micro air vehicles., Particle image velocimetry., Pitching (Aerodynamics).
http://etd.lib.metu.edu.tr/upload/12615239/index.pdf
https://hdl.handle.net/11511/22220
Graduate School of Natural and Applied Sciences, Thesis

Suggestions

Measurement of leading and trailing edge vortex shedding mechanism for flapping airfoil in hover using particle image velocimetry technique
Çekinmez, Aybüge; Alemdaroğlu, Hüseyin Nafiz; Department of Aerospace Engineering (2013)
In this thesis, the vortex shedding formation/mechanism for flapping airfoil making the figure of eight motion in hover is investigated experimentally using Particle Image Velocimetry (PIV) technique and numerically for some parameters determined. For this investigation, a new flapping mechanism is designed and implemented to the existing water tank, where the airfoil is traversed laterally, such that the motion depicts a figure of eight. The traversing system is moved both in x (horizontal) and y (vertical...
Experimental investigation of 3D flow field around a Flapping wing making figure-of-eight motion in hover Using PIV technique
Ersöz, İrem; Alemdaroğlu, Hüseyin Nafiz; Department of Aerospace Engineering (2014)
This thesis presents the results of experimental investigation of vortex formation around a three dimensional flapping wing making figure-of-eight motion in hovering flight at low Reynolds numbers. These results are compared with those obtained from previous computational and experimental studies of the same flapping motions. Analysis of vortex formations around the three dimensional flapping wing and the investigations of the effect of different parameters such as the amplitude of motion in y direction and...
Numerical simulation of scour at the rear side of a coastal revetment
Şentürk, Barış Ufuk; Guler, Hasan Gokhan; Baykal, Cüneyt (2023-05-01)
This paper presents the results of a numerical modeling study on the scouring of unprotected rear side material of a rubble mound coastal revetment due to the overtopping of solitary-like waves utilizing a coupled hydro-morphodynamic computational fluid dynamics (CFD) model. Three cases having various wave heights are tested with six different turbulence models together with different wall functions. The hydrodynamic results (free-surface elevations, overtopping volumes, and jet thicknesses) and morphologic...
Experimental Investigation of the Effects of Winglets on the Tip Vortex Behavior of a Model Horizontal Axis Wind Turbine Using Particle Image Velocimetry
Ostovan, Yasar; Akpolat, M. Tugrul; Uzol, Oğuz (2019-02-01)
This study presents an experimental investigation on the effects of winglets on the near wake flow around the tip region and on the tip vortex characteristics downstream of a 0.94 m diameter three-bladed horizontal axis wind turbine (HAWT) rotor. Phase-locked 2D particle image velocimetry (PIV) measurements are performed with and without winglets covering 120 deg of azimuthal progression of the rotor. The impact of using winglets on the flow field near the wake boundary as well as on the tip vortex characte...
Nonlinear 3D Modeling and Vibration Analysis of Horizontal Drum Type Washing Machines
Baykal, Cem; Ciğeroğlu, Ender; Yazıcıoğlu, Yiğit (2020-01-01)
In this study, a nonlinear 3-D mathematical model for horizontal drum type washing machines is developed considering rotating unbalance type excitation. Nonlinear differential equations of motion are converted into a set of nonlinear algebraic equations by using Harmonic Balance Method (HBM). The resulting nonlinear algebraic equations are solved by using Newton’s method with arc-length continuation. Several case studies are performed in order to observe the effects of orientation angles of springs and damp...
Citation Formats
H. Hızlı, “Numerical and experimental investigation of pitching / plunging airfoils in hover,” M.S. - Master of Science, Middle East Technical University, 2012.
METU IIS - Integrated Information Service open@metu.edu.tr