Complex terrain effects on wake characteristics of a parked wind turbine

Allori

Bartoli

et al. 2019

TFAMENA

Self Cite

Hilly terrain may considerably influence energy yield and structural loading of wind turbines. Wind energy developers are therefore required to accurately predict wind characteristics at the wind farm site already in the designing phase. It is necessary to determine how particular hill shape and size affect wind characteristics at the location of wind turbines operating in the wake of a hill. In order to address this complex issue, small-scale laboratory experiments were carried out in a boundary layer wind tunnel (BLWT). The focus was on characteristics of the flow at the same position downstream of the hill and the wind turbine models studied on various sizes and shapes of the hill model. Three hill models (a small and a large hill with laterally uniform heights and a hill with a bay) were exposed to the thermally neutrally stratified atmospheric boundary layer (ABL) simulation. In each experiment, there was only one hill model in the BLWT test section. The configuration without the hill, i.e. the flat terrain model, was tested as a reference case. Downstream of the hill model, there was a single (alone-standing) wind turbine model. Flow characteristics were studied downstream (behind) the wind turbine model. The wind turbine model was in the parking position in order to study wind characteristics in the situation with a strong wind when there is no rotation of rotor blades. The experimental results indicate a velocity decrease and stronger turbulence in the wind turbine wake in the presence of a hill, which trend is more pronounced in the case of larger hills. Strong velocity gradients are observed around the hub height in the large hill configuration, while this velocity deficit is the smallest in the hill with a bay configuration due to flow channeling. The velocity power spectra reveal the characteristic peak due to the vortex shedding from the hill ridge. The obtained results provide a new insight into the turbulent wake characteristics of a single wind turbine placed downstream of a hill with a potential to serve as a validation tool for computational studies.

Section: Methodsmentioning

confidence: 99%

Section: Wind Turbine Wake Characteristicsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Wind Characteristics in the Wake of a Non-Rotating Wind Turbine close to a Hill

Allori

Bartoli

et al. 2019

TFAMENA

Self Cite

“…While aerodynamic loads on wind turbines were previously thoroughly investigated for cases, where wind turbines were placed on flat terrain and open sea, the characteristics of atmospheric flow and turbulence around wind turbines in complex terrain, as well as their aerodynamic loads, are fairly unknown [2]. Nevertheless, studies on effects of complex terrain on wind-turbine wake characteristics, like for example [3] and [4] are quite rare, despite the fact that topographical features are likely to considerably influence the atmospheric turbulence and thus wind turbine aerodynamics.…”

Section: Introductionmentioning

confidence: 99%

Scaling of wind turbine aerodynamics: wind tunnel experiments

Macháček¹,

Pospı́šil²,

2020

MATEC Web Conf.

Self Cite

A small-scale wind turbine model was designed and manufactured to study its aerodynamic thrust force and the harvested flow energy. To provide a good understanding of the aerodynamics of the small-scale wind turbine at the low Reynolds number, the performance of three different types of blade airfoils was studied. The main motivation for the design of a new miniature wind turbine model was to achieve realistic values of the thrust force and the power coefficient on the model scale. A new blade profile with a thickness of 10% was designed and employed to reach the high tip-speed ratio, which is characteristic of contemporary wind turbines.

“…An important and still open issues are related to wind characteristics around wind turbines placed in topographically complex terrain, [47], and in regions characterized by non-standard transient winds, [48], particularly in case of extreme weather conditions encountered during summer, [49], and winter, [50]. These untypical wind conditions can considerably increase structural fatigue of wind turbines and thus shorten their lifetime, while the power output of wind turbines in these transient wind conditions is smaller than it is the case for quasi-steady flow conditions.…”

mentioning

confidence: 99%

Feasibility of Investment in Renewable Energy Systems for Shipyards

Hadžić

Tomić

2018

brod

Self Cite

SummaryShipbuilding industry is generally considered as one of the key global industries. It consumes a significant amount of energy and leaves a strong footprint on the environment. It is therefore required to try to increase renewable energy sources in the shipbuilding industry in accordance with the adopted international legislation. This will improve energy efficiency of shipyards and reduce their impact on the environment. The present preliminary study contributes to those goals as application of sustainable renewable energy systems in ship production industry is considered. The analysis is performed for solar panels, tidal and wind turbines with respect to their technology readiness and investment costs, as well as for the total energy consumption. While in the present work the research hypothesis is studied on example of a typical Croatian shipyard, the general findings are expected to be widely applicable to all shipyards. The solar panels are considered as the most suitable renewable technology, while the investment return period for introducing solar panels to satisfy the entire electrical energy demand in this particular case is approximately seven years. The impact of introducing this green shipbuilding approach is considered beneficial in comparison with current conventional electrical energy production based on conventional energy sources.