Show/Hide Menu
Hide/Show Apps
Logout
Türkçe
Türkçe
Search
Search
Login
Login
OpenMETU
OpenMETU
About
About
Open Science Policy
Open Science Policy
Open Access Guideline
Open Access Guideline
Postgraduate Thesis Guideline
Postgraduate Thesis Guideline
Communities & Collections
Communities & Collections
Help
Help
Frequently Asked Questions
Frequently Asked Questions
Guides
Guides
Thesis submission
Thesis submission
MS without thesis term project submission
MS without thesis term project submission
Publication submission with DOI
Publication submission with DOI
Publication submission
Publication submission
Supporting Information
Supporting Information
General Information
General Information
Copyright, Embargo and License
Copyright, Embargo and License
Contact us
Contact us
Experimental Investigation of the Effects of Winglets on the Tip Vortex Behavior of a Model Horizontal Axis Wind Turbine Using Particle Image Velocimetry
Download
index.pdf
Date
2019-02-01
Author
Ostovan, Yasar
Akpolat, M. Tugrul
Uzol, Oğuz
Metadata
Show full item record
This work is licensed under a
Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License
.
Item Usage Stats
292
views
351
downloads
Cite This
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 characteristics such as the vortex convection, vortex core size, and core expansion as well as the resultant induced drag on the rotor are investigated. Results show that winglets initially generate an asymmetric co-rotating vortex pair, which eventually merge together after about ten tip chords downstream to create a single but nonuniform vortex structure. Mutual induction of the initial double vortex structure causes a faster downstream convection and a radially outward motion of tip vortices compared to the baseline case. The wake boundary is shifted radially outward, velocity gradients are diffused, and vorticity and turbulent kinetic energy levels are significantly reduced across the wake boundary. The tip vortex core sizes are three times as big compared to those of the baseline case, and within the vortex core, vorticity and turbulent kinetic energy levels are reduced more than 50%. Results show consistency with various vortex core and expansion models albeit with adjusted model coefficients for the winglet case. The estimated induced drag reduction is about 15% when winglets are implemented.
Subject Keywords
Tip Vortex
,
Winglets
,
Wind Turbine Wakes
,
Particle Image Velocimetry
URI
https://hdl.handle.net/11511/42694
Journal
JOURNAL OF SOLAR ENERGY ENGINEERING-TRANSACTIONS OF THE ASME
DOI
https://doi.org/10.1115/1.4041154
Collections
Department of Aerospace Engineering, Article
Suggestions
OpenMETU
Core
Experimental investigation of tip anhedral effects on the aerodynamics of a model helicopter rotor in hover
Uluocak, Sinem; Perçin, Mustafa; Uzol, Oğuz (2021-06-01)
This study experimentally investigates the effects of tip anhedral on the rotor aerodynamic performance and the tip vortex characteristics in hovering flight. A five-bladed scaled helicopter rotor with blades that have either rectangular (baseline) or anhedral tip geometries was used as the experimental model. Thrust and torque measurements were performed at the tip Mach numbers (Mtip) of 0.3 and 0.4 at five different pitch angles. In addition, flow field measurements via phase-locked particle image velocim...
Experimental investigation of the effects of tip-injection on the aerodynamic loads and wake characteristics of a model horizontal axis wind turbine rotor
Abdulrahim, Anas; Uzol, Oğuz; Department of Aerospace Engineering (2014)
In this study, tip injection is implemented on a model Horizontal Axis Wind Turbine (HAWT) rotor to investigate the power and thrust coefficient variations as well as the wake characteristics. The model wind turbine has a 0.95 m diameter 3-bladed rotor with non-linearly twisted and tapered blades that has NREL S826 profile. The nacelle, hub and the blades are specifically designed to allow pressurized air to pass through and get injected from the tips while the rotor is rotating. The experiments are perform...
Experimental investigation of the effects of different helicopter rotor tip geometries on aerodynamic performance and tip vortex characteristics
Uluocak, Sinem; Hazaveh, Hooman Amiri; Perçin, Mustafa; Akpolat, M Tuğrul; Uzol, Oğuz (Netherlands Association of Aeronautical Engineers; 2018-09-05)
In this study, the effects of different tip geometries (rectangular, anhedral, swept-tapered and swept-tapered-anhedral) on the rotor hover performance and tip vortex characteristics are investigated experimentally. A scaled rotor model set-up, instrumented with thrust and torque sensors, is used for aerodynamic performance measurements in hover and a two-dimensional (2D) particle image velocimetry (PIV) is used to obtain the tip vortex characteristics such as vortex trajectory, maximum tangential velocity,...
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...
Experimental study on power curtailment of three in-line turbines
Bartl, Jan; Ostovan, Yasar; Uzol, Oğuz; Saetran, Lars (Elsevier BV; Elsevier BV; 2017-01-20)
A dataset of wind tunnel power and wake flow measurements on a setup of three aligned model wind turbines is presented. The power outputs of the three turbines are in good agreement with measurements from a full-scale wind farm of similar inter-turbine spacing. A comparison of the wake flow behind the first row and the second row shows a significantly higher mean velocity loss behind the second row justifying a further power drop from the second to the third row turbine. Curtailing the front row turbine to ...
Citation Formats
IEEE
ACM
APA
CHICAGO
MLA
BibTeX
Y. Ostovan, M. T. Akpolat, and O. Uzol, “Experimental Investigation of the Effects of Winglets on the Tip Vortex Behavior of a Model Horizontal Axis Wind Turbine Using Particle Image Velocimetry,”
JOURNAL OF SOLAR ENERGY ENGINEERING-TRANSACTIONS OF THE ASME
, pp. 0–0, 2019, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/42694.