Master Degree / Yüksek Lisans Tezleri
Permanent URI for this collectionhttps://hdl.handle.net/11147/3008
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Master Thesis Atmospheric Effects on Short Term Wind Power Forecasting(01. Izmir Institute of Technology, 2021) Kalay, Yüksel; Bingöl, Ferhat; Bingöl, Ferhat; Bingöl, Ferhat; 01. Izmir Institute of Technology; 03.06. Department of Energy Systems Engineering; 03. Faculty of EngineeringWind power all over the world are being popularizing unlike decrease in conventional sources due to environmental issues. However, power acquired from wind is not stable during day and night, which means that intermittent due to nature of the source. Forecasting in wind power plant is very challenging compared to forecasting of production of conventional power plant. Although there are many robust and site-specific models in order to forecast wind power accurately, decrease of deviation in wind power forecasting by using statistical, physical and hybrid models is still open to new approaches. In this study, four different forecast models based numerical weather prediction (NWP) models for three different wind farms which have different atmospheric conditions are examined to improve wind farm-based power forecasting. For this purpose, wind power forecasting of the providers was categorized based on atmospheric effects, which are site temperature and turbulence. Results have been compared with real time power production from wind turbine supervisory control and data acquisition (SCADA) system. Afterwards, new method based on selecting best provider for specific condition was developed by considering atmospheric effects on power forecasting. It should be noted that the method is an engineering approach, not a new forecast model. In many cases, newly developed method has succeeded to outperform in comparison to results belonging to forecast providers. Hourly and daily wind power forecasting that have significant role in electricity market has been improved for selected wind farms by the help of an engineering approach used in this study. Same method is also implementable to another wind farm if required inputs exist.Master Thesis Modification of a Computational Fluid Dynamics Model (ansys-Fluent) for the Purpose of River Flow and Sediment Transport Modeling(Izmir Institute of Technology, 2015) Ekmekçi, Hüseyin Burak; Elçi, Şebnem; Elçi, Şebnem; 03.03. Department of Civil Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyPrecise estimation of the sediment transport and settling velocity of particle in turbulent flows is required for many engineering applications including modeling of the transport of suspended sediments and the transport of particle pollutants. This study presents an approach for modification of an existing CFD Model for sediment transport in turbulent flow based on field measurements. In the first part, synchronized 3-D velocity and temperature time series were monitored at Büyük Menderes River in Turkey where the data were utilized to characterize the turbulence characteristics and model particle – fluid interaction. Sieve and hydrometer analysis were obtained from earlier studies to understand and modify sediment transport under different conditions via ANSYS Fluent programme. The second part of the study involved numerical modeling of hydrodynamics via 3D CFD model in the selected portion of a river body through use of field measurements conducted at the study site. The k-ω turbulence model found to be the best suited when such flow around a structure as piers or flow through a water intake is considered. Effect of particle size, concentration and modeling approach for particle motion are also investigated and Rossin Rammler Logarithmic Distribution and multiphase modeling approach was the most appropriate methods. This study involved development of an approach to modify drag force on sediment particles using turbulence characteristics in the Fluent solver as well.Master Thesis Turbulence Measurements in the Wall Jet Layer of Impinging Round Jet(Izmir Institute of Technology, 2012) Malak, Serdar; Özkol, Ünver; Özkol, Ünver; 03.10. Department of Mechanical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyThe objective of this thesis is to understand how turbulence affects the impinging jet flow and heat transfer mechanism under acoustic actuaion. This work is based upon the experimental work including velocity and turbulence measurements in various cases and is a continuation of studies of Necati Bilgin and Orcun Kor . Acoustic actuation is provided by a loudspeaker controlled by a function generator. Acoustic waves generated by the loudspeaker reaches nozzle and formed periodic fluctuations in flow. Strouhal number, which is dimensionless reperentation of actuation frequeny, is varied in the range of 0<St<1. Nozzle exit velocity is controlled by Reynolds number whics is kept constant around 10000. Velocity and turbulence measurements were performed by using a hot-wire sensor. Measurements are performed in the radial direction ranging from the jet centerline (x/D=0) to 2.4D for jet profile data and to 8.5D for near wall data. Wall normal measurement locations are at z/D=5.8, 5, 4, 3, 2, 1, 0.2 for jet profile data and at z/D=5.8 for near wall data. The distance between data points is kept at 0.1D.