ON THE EFFECTS OF INFLOW CONDITIONS ON THE WAKE OF WIND TURBINE MODELS AND POROUS DISCS

Download

thesis_FINAL_ABDELRHAMAN HASSANEIN_2.pdf

Date

2023-1-18

Author

Hassanein, Abdelrahman Hisham Ahmed Sabri

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

326
views

202
downloads

The study investigates the effect of two inflow conditions on the wake of a model wind turbine, namely, homogenous isotropic turbulence intensity and streamwise gust. For the effect of the freestream turbulence intensity, the wake of a porous disc with a comparable thrust coefficient was used to further highlight the differences in their wakes and decay characteristics. Results show that the wake of a wind turbine model has a faster decay rate than porous discs under both freestream turbulence intensities. In addition, the wake of both models was scaled to show a collapsing self-similar wake profile. Furthermore, the decay of the maximum velocity deficit was curve fitted using a logarithmic fit where the slope of the fit was used to provide a new way to quantify the wake growth. Consequently, this could be used as a basis for a new analytical model for the far wake of wind turbines. The effects of a streamwise gust with a triangular temporal distribution on the wake of a wind turbine model were studied for three tip speed ratios. Results reveal different wake evolutions for the three cases. Furthermore, the wake profiles under gust were scaled to collapse on self-similar profiles. Moreover, the wake of the wind turbine model at a tip speed ratio of two and under triangular gust was compared to a top hat gust profile to investigate the effects of gust profiles. It was shown that the wake flow and, thus, the thrust generation mechanism of the turbine respond similarly during the rising edges of both gust profiles.

Subject Keywords

Wake, Gust, Wind turbine, Wind tunnel, active grid

URI

https://hdl.handle.net/11511/102057

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Effects of mie vanes and tip injection on the performance and wake characteristics of HAWT Anik, Ezgi; Abdulrahim, Anas; Uzol, Oğuz (null; 2016-01-08) This paper presents the results of an experimental study that focuses on the tip leakage/vortex control of a model horizontal axis wind turbine rotor. The effects of Mie vanes and tip injection on the performance and wake characteristics of a model horizontal axis wind turbine rotor are investigated through experiments that are conducted by placing a specially designed three-bladed horizontal axis wind turbine rotor at the exit of an open-jet wind tunnel facility. The rotor blades are non-linearly twisted a...
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 ...
AMBIENT TURBULENCE INTENSITY EFFECTS ON THE CHARACTERISTICS OF WAKE DEVELOPMENT OF A MODEL WIND TURBINE AND A MATCHED POROUS DISC Öztürk, Buğrahan; Uzol, Oğuz; Department of Aerospace Engineering (2022-9-1) This thesis study aims to observe the ambient turbulence intensity effects on the wake development of a model wind turbine and a matched porous disc. Comprehensive wind tunnel experiments are conducted in the wake of the model wind turbine and the porous disc up to 7 diameters downstream through two-dimensional two-component particle velocimetry. The wakes of the model wind turbine and the porous disc are investigated in terms of the mean flow field, turbulence, wake decay, and wake spreading characteristic...
GENERATION AND EXPERIMENTAL INVESTIGATIONS OF GUSTY FLOWS IN WIND TUNNELS Andırın, Mert Ali; Uzol, Oğuz; Perçin, Mustafa; Department of Aerospace Engineering (2022-6-16) Wind tunnels are designed to operate at low turbulence intensities, which makes it unfeasible to study the turbulent and gusty flows that are observed in nature and in engineering applications. To conduct such studies number of unconventional methods are adopted in wind tunnels, one of which is the use of active grids. Active grids consist of motor-driven rods which accommodate flaps and they are generally placed at the inlet of wind tunnel test sections. By regulating the motion of the agitator wings, flow...
Comparative study of transient and quasi-steady aeroelastic analysis of composite wind turbine blade in steady wind conditions Sargın, Hakan; Kayran, Altan; Department of Aerospace Engineering (2014) The objective of this study is to conduct a comparative study of the transient and quasi-steady aeroelastic analysis of a composite wind turbine blade in steady wind conditions. Transient analysis of the wind turbine blade is performed by the multi-body dynamic code Samcef Wind Turbine which uses blade element momentum theory for aerodynamic load calculation. For this purpose, a multi-body wind turbine model is generated with rigid components except for the turbine blades. For the purposes of the study, a r...

Citation Formats

A. H. A. S. Hassanein, “ON THE EFFECTS OF INFLOW CONDITIONS ON THE WAKE OF WIND TURBINE MODELS AND POROUS DISCS,” M.S. - Master of Science, Middle East Technical University, 2023.