Measurement of leading and trailing edge vortex shedding mechanism for flapping airfoil in hover using particle image velocimetry technique

Çekinmez, Aybüge
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) directions such that the figure of eight is drawn. This is the type of flapping motion for some of the birds in nature. The amplitude and the frequency of oscillations can easily be adjusted. The PIV technique is used to put into evidence the vortex shedding mechanism from the leading and trailing edges of the airfoil. Experiments are performed to investigate the effects of the parameters which are the amplitude of the figure of eight flapping motion, initial angle of attack, and the shape of the airfoil. From these experiments, the unsteady behavior of the vortices shed from the airfoil is analyzed and their effect on the generation of lift and drag is investigated. Also, the numerical study performed for the some parameters in present and previously done by Başkan [10] is supported and completed by this experimental study.


Numerical and experimental investigation of pitching / plunging airfoils in hover
Hızlı, Hasan; Kurtuluş, Dilek Funda; Department of Aerospace Engineering (2012)
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 applica...
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...
Measurement of the transverse momentum spectra of weak vector bosons produced in proton-proton collisions at root s=8TeV
Khachatryan, V.; et. al. (Springer Science and Business Media LLC, 2017-02-01)
The transverse momentum spectra of weak vector bosons are measured in the CMS experiment at the LHC. The measurement uses a sample of proton-proton collisions at root s = 8TeV, collected during a special low-luminosity running that corresponds to an integrated luminosity of 18: 4 +/- 0: 5 pb(-1). The production of W bosons is studied in both electron and muon decay modes, while the production of Z bosons is studied using only the dimuon decay channel. The ratios of W- to W+ and Z to W di ff erential cross s...
Measurement of the groomed jet mass in PbPb and pp collisions at root s(NN)=5:02 TeV
Sirunyan, A. M.; et. al. (Springer Science and Business Media LLC, 2018-10-01)
A measurement of the groomed jet mass in PbPb and pp collisions at a nucleon-nucleon center-of-mass energy of 5.02 TeV with the CMS detector at the LHC is presented. Jet grooming is a recursive procedure which sequentially removes soft constituents of a jet until a pair of hard subjets is found. The resulting groomed jets can be used to study modifications to the parton shower evolution in the presence of the hot and dense medium created in heavy ion collisions. Predictions of groomed jet properties from th...
Measurement of the charge asymmetry in top-quark pair production in proton-proton collisions at root s=7 TeV
Chatrchyan, S.; et. al. (Elsevier BV, 2012-03-01)
The difference in angular distributions between top quarks and antiquarks, commonly referred to as the charge asymmetry, is measured in pp collisions at the LHC with the CMS experiment. The. data sample corresponds to an integrated luminosity of 1.09 fb(-1) at a centre-of-mass energy of 7 TeV. Top-quark pairs are selected in the final state with an electron or muon and four or more jets. At least one jet is identified as originating from b-quark hadronization. The charge asymmetry is measured in two variabl...
Citation Formats
A. Çekinmez, “Measurement of leading and trailing edge vortex shedding mechanism for flapping airfoil in hover using particle image velocimetry technique,” M.S. - Master of Science, Middle East Technical University, 2013.