In this study, the impact of growth in turbine size on aerodynamic rotor performance of modern co... more In this study, the impact of growth in turbine size on aerodynamic rotor performance of modern commercial large-scale wind turbines was investigated. For this examination, three different commercial large-scale wind turbines of models VESTAS V80-2MW, V90-3MW, and V126-3.3MW operating on three existing onshore wind farms were selected. In order to determine the effects of turbine size growth on aerodynamic rotor performance, turbine power output P, turbine power coefficient, Cp, turbine rotational speed, Ω, thrust force, T, tip speed ratio, λ, and flow angle, ϕ, values obtained from these turbines were compared at the same magnitude of free-stream wind speeds, U∞. The results reveal that decreasing specific power decreases the rated output wind speed of the wind turbines; hence, the reduction in the rated output of wind speed contributes to the tendency of higher power capacity. Moreover, it was determined that the enlargement in the turbine size has a profound influence on the parameters that affect the performance of the turbine such as rotational speed, Ω, thrust force, T, tip-speed ratio, λ, and flow angle, ϕ. For instance, higher thrust loads and tip-speed ratios were acquired for the turbines having a larger rotor diameter which results in better aerodynamic efficiency of the turbine.
Present study numerically investigates the flow field and heat transfer of water in two dimension... more Present study numerically investigates the flow field and heat transfer of water in two dimensional sinusoidal and rectangular corrugated wall channels. Simulations are performed for fully developed flow conditions at inlet sections of the channels that have 12 waves. The temperature of the input fluid is taken to be less than that temperature of wavy walls. The governing continuity, momentum and energy equations are numerically solved using finite volume method based on SIMPLE technique. The investigation covers Reynolds number in the rage of 100-1000. The effects of the distance between upper and lower corrugated walls are studied by varying Hmin/Hmax ratio from 0.3 to 0.5 for keeping wave length and wave amplitude values fixed for both geometries. The effects of the wall geometry, Reynolds number and the distance between walls on the flow characteristics, the local Nusselt number and heat transfer are studied. It is found that heat transfer enhancement increases by usage of corru...
AbstractThe objective of this work is to reveal the significance of a trailing-edge attachment on... more AbstractThe objective of this work is to reveal the significance of a trailing-edge attachment on the flow structure over a generic nonslender delta wing using the dye visualization technique on th...
In this study, artificial neural networks (ANNs) were applied to predict the mean monthly wind sp... more In this study, artificial neural networks (ANNs) were applied to predict the mean monthly wind speed of any target station using the mean monthly wind speeds of neighboring stations which are indicated as reference stations. Hourly wind speed data, collected by the Turkish State Meteorological Service (TSMS) at 8 measuring stations located in the eastern Mediterranean region of Turkey were used. The long-term wind data, containing hourly wind speeds, directions and related information, cover the period between 1992 and 2001. These data were divided into two sections. According to the correlation coefficients, reference and target stations were defined. The mean monthly wind speeds of reference stations were used and also corresponding months were specified in the input layer of the network. On the other hand, the mean monthly wind speed of the target station was utilized in the output layer of the network. Resilient propagation (RP) learning algorithm was applied in the present simu...
Bu calismada, Turkiye’nin ruzgâr enerjisi durumu etraflica arastirilmistir. Bu baglamda, gunumuzu... more Bu calismada, Turkiye’nin ruzgâr enerjisi durumu etraflica arastirilmistir. Bu baglamda, gunumuzun en populer ve gelecek vaat eden yenilenebilir enerji turlerinden birisi olan ruzgâr enerjisi uygulamalari, Turkiye icin, 2009 ile 2018 yil araligini kapsayacak sekilde incelenmistir. En son olarak ise, Turkiye’nin 2030 yilina kadar olan uzun vadeli ruzgar enerjisi durumu tahmin edilmistir. Bu kapsamda, Turkiye’nin 2030 yilindaki ruzgâr enerjisi durumunun, 2018’deki durumunu bile asacagi gosterilmistir; soyle ki, ruzgar enerjisinin, 2018 yilinda, tum enerjilere gore verilen orani olan %16,56’lik degerinin, 2030 yilinda asilarak, %16,61’lik degere ulasacagi beklenmektedir.
Present experimental study aims to examine flow differences generated by common flow up (CFU) and... more Present experimental study aims to examine flow differences generated by common flow up (CFU) and common flow down (CFD) vortex generator (VG) pairs fixed to the slant surfaces of an equilateral triangular duct. The flow differences were examined in detail in terms of formation of second set of twin vortices under different Reynolds number and duct conditions. It is concluded that the formation of twin vortices occurs an earlier downwind distance regardless of the value of Reynolds number and as the Reynolds number is increased from 3000 to 8000 the twin vortices disappear earlier in the case of CFD comparing to the case of CFU.
International Journal of Numerical Methods for Heat & Fluid Flow
Purpose This paper aims to exhibit a numerical study to analyze the influence of a periodic magne... more Purpose This paper aims to exhibit a numerical study to analyze the influence of a periodic magnetic source on free convection flow and entropy generation of a ferrofluid in a baffled cavity. In this study, ferrofluid nanofluid was selected due to its ability to image magnetic domain structures within the cavity. The non-uniform magnetic source is considered as a sinusoidal distribution in the vertical direction. Design/methodology/approach The finite volume technique is used to evaluate the steady two-dimensional partial differential equations that govern the flow with its corresponding boundary conditions. Findings The obtained results indicate that a significant increase in the average Nusselt number can be achieved with the use of the periodic magnetic source instead of a uniform case. In addition, the effectiveness of the adiabatic baffle notably depends on its position and Rayleigh number. Regardless of the values of period and Hartmann numbers, the periodic magnetic source ha...
Energy Sources, Part A: Recovery, Utilization, and Environmental Effects
The main purpose of the study was to obtain the design parameters of optimum wind turbine linear ... more The main purpose of the study was to obtain the design parameters of optimum wind turbine linear shrouding bodies to enhance wind turbine performance further. The blade element momentum theory and ...
The primary purpose of this investigation is to observe the effect of the pitching motion on the ... more The primary purpose of this investigation is to observe the effect of the pitching motion on the vortical flow structure and bursting of leading-edge vortices over a delta wing under the sideslip angle, β using a dye visualization technique. In the current work, a delta wing with a sweep angle of Λ = 70° was oscillated in upstroke and downstroke direction to be able to discover the influence of pitching motion on the flow characteristics of the delta wing. The values of mean angles of attack were selected as αm = 25° and αm = 35°, and the sideslip angle was altered from β = 0 to 16°. The delta wing oscillated with the various periods of Te = 5 s, 20 s, and 60 s, respectively. Amplitude of motion was adjusted as αo = ± 5°. It is found that the pitching motion of the delta wing under the sideslip angle β varies the location of the vortex bursting and vortical flow structure substantially.
Wind turbine technology in the world has been developed by continuously improving turbine perform... more Wind turbine technology in the world has been developed by continuously improving turbine performance, design, and efficiency. Over the last 40 years, the rated capacity and dimension of the commercial wind turbines have increased dramatically, so the energy cost has declined significantly, and the industry has moved from an idealistic position to an acknowledged component of the power generation industry. For this reason, a thorough examination of the aerodynamic rotor performance of a modern large-scale wind turbine working on existing onshore wind farms is critically important to monitor and control the turbine performance and also for forecasting turbine power. This study focuses on the aerodynamic rotor performance of a 3300-kW modern commercial large-scale wind turbine operating on an existing onshore wind farm based on the measurement data. First, frequency distributions of wind speeds and directions were obtained using measurements over one year. Then, wind turbine parameter...
In this study, the impact of growth in turbine size on aerodynamic rotor performance of modern co... more In this study, the impact of growth in turbine size on aerodynamic rotor performance of modern commercial large-scale wind turbines was investigated. For this examination, three different commercial large-scale wind turbines of models VESTAS V80-2MW, V90-3MW, and V126-3.3MW operating on three existing onshore wind farms were selected. In order to determine the effects of turbine size growth on aerodynamic rotor performance, turbine power output P, turbine power coefficient, Cp, turbine rotational speed, Ω, thrust force, T, tip speed ratio, λ, and flow angle, ϕ, values obtained from these turbines were compared at the same magnitude of free-stream wind speeds, U∞. The results reveal that decreasing specific power decreases the rated output wind speed of the wind turbines; hence, the reduction in the rated output of wind speed contributes to the tendency of higher power capacity. Moreover, it was determined that the enlargement in the turbine size has a profound influence on the parameters that affect the performance of the turbine such as rotational speed, Ω, thrust force, T, tip-speed ratio, λ, and flow angle, ϕ. For instance, higher thrust loads and tip-speed ratios were acquired for the turbines having a larger rotor diameter which results in better aerodynamic efficiency of the turbine.
Present study numerically investigates the flow field and heat transfer of water in two dimension... more Present study numerically investigates the flow field and heat transfer of water in two dimensional sinusoidal and rectangular corrugated wall channels. Simulations are performed for fully developed flow conditions at inlet sections of the channels that have 12 waves. The temperature of the input fluid is taken to be less than that temperature of wavy walls. The governing continuity, momentum and energy equations are numerically solved using finite volume method based on SIMPLE technique. The investigation covers Reynolds number in the rage of 100-1000. The effects of the distance between upper and lower corrugated walls are studied by varying Hmin/Hmax ratio from 0.3 to 0.5 for keeping wave length and wave amplitude values fixed for both geometries. The effects of the wall geometry, Reynolds number and the distance between walls on the flow characteristics, the local Nusselt number and heat transfer are studied. It is found that heat transfer enhancement increases by usage of corru...
AbstractThe objective of this work is to reveal the significance of a trailing-edge attachment on... more AbstractThe objective of this work is to reveal the significance of a trailing-edge attachment on the flow structure over a generic nonslender delta wing using the dye visualization technique on th...
In this study, artificial neural networks (ANNs) were applied to predict the mean monthly wind sp... more In this study, artificial neural networks (ANNs) were applied to predict the mean monthly wind speed of any target station using the mean monthly wind speeds of neighboring stations which are indicated as reference stations. Hourly wind speed data, collected by the Turkish State Meteorological Service (TSMS) at 8 measuring stations located in the eastern Mediterranean region of Turkey were used. The long-term wind data, containing hourly wind speeds, directions and related information, cover the period between 1992 and 2001. These data were divided into two sections. According to the correlation coefficients, reference and target stations were defined. The mean monthly wind speeds of reference stations were used and also corresponding months were specified in the input layer of the network. On the other hand, the mean monthly wind speed of the target station was utilized in the output layer of the network. Resilient propagation (RP) learning algorithm was applied in the present simu...
Bu calismada, Turkiye’nin ruzgâr enerjisi durumu etraflica arastirilmistir. Bu baglamda, gunumuzu... more Bu calismada, Turkiye’nin ruzgâr enerjisi durumu etraflica arastirilmistir. Bu baglamda, gunumuzun en populer ve gelecek vaat eden yenilenebilir enerji turlerinden birisi olan ruzgâr enerjisi uygulamalari, Turkiye icin, 2009 ile 2018 yil araligini kapsayacak sekilde incelenmistir. En son olarak ise, Turkiye’nin 2030 yilina kadar olan uzun vadeli ruzgar enerjisi durumu tahmin edilmistir. Bu kapsamda, Turkiye’nin 2030 yilindaki ruzgâr enerjisi durumunun, 2018’deki durumunu bile asacagi gosterilmistir; soyle ki, ruzgar enerjisinin, 2018 yilinda, tum enerjilere gore verilen orani olan %16,56’lik degerinin, 2030 yilinda asilarak, %16,61’lik degere ulasacagi beklenmektedir.
Present experimental study aims to examine flow differences generated by common flow up (CFU) and... more Present experimental study aims to examine flow differences generated by common flow up (CFU) and common flow down (CFD) vortex generator (VG) pairs fixed to the slant surfaces of an equilateral triangular duct. The flow differences were examined in detail in terms of formation of second set of twin vortices under different Reynolds number and duct conditions. It is concluded that the formation of twin vortices occurs an earlier downwind distance regardless of the value of Reynolds number and as the Reynolds number is increased from 3000 to 8000 the twin vortices disappear earlier in the case of CFD comparing to the case of CFU.
International Journal of Numerical Methods for Heat & Fluid Flow
Purpose This paper aims to exhibit a numerical study to analyze the influence of a periodic magne... more Purpose This paper aims to exhibit a numerical study to analyze the influence of a periodic magnetic source on free convection flow and entropy generation of a ferrofluid in a baffled cavity. In this study, ferrofluid nanofluid was selected due to its ability to image magnetic domain structures within the cavity. The non-uniform magnetic source is considered as a sinusoidal distribution in the vertical direction. Design/methodology/approach The finite volume technique is used to evaluate the steady two-dimensional partial differential equations that govern the flow with its corresponding boundary conditions. Findings The obtained results indicate that a significant increase in the average Nusselt number can be achieved with the use of the periodic magnetic source instead of a uniform case. In addition, the effectiveness of the adiabatic baffle notably depends on its position and Rayleigh number. Regardless of the values of period and Hartmann numbers, the periodic magnetic source ha...
Energy Sources, Part A: Recovery, Utilization, and Environmental Effects
The main purpose of the study was to obtain the design parameters of optimum wind turbine linear ... more The main purpose of the study was to obtain the design parameters of optimum wind turbine linear shrouding bodies to enhance wind turbine performance further. The blade element momentum theory and ...
The primary purpose of this investigation is to observe the effect of the pitching motion on the ... more The primary purpose of this investigation is to observe the effect of the pitching motion on the vortical flow structure and bursting of leading-edge vortices over a delta wing under the sideslip angle, β using a dye visualization technique. In the current work, a delta wing with a sweep angle of Λ = 70° was oscillated in upstroke and downstroke direction to be able to discover the influence of pitching motion on the flow characteristics of the delta wing. The values of mean angles of attack were selected as αm = 25° and αm = 35°, and the sideslip angle was altered from β = 0 to 16°. The delta wing oscillated with the various periods of Te = 5 s, 20 s, and 60 s, respectively. Amplitude of motion was adjusted as αo = ± 5°. It is found that the pitching motion of the delta wing under the sideslip angle β varies the location of the vortex bursting and vortical flow structure substantially.
Wind turbine technology in the world has been developed by continuously improving turbine perform... more Wind turbine technology in the world has been developed by continuously improving turbine performance, design, and efficiency. Over the last 40 years, the rated capacity and dimension of the commercial wind turbines have increased dramatically, so the energy cost has declined significantly, and the industry has moved from an idealistic position to an acknowledged component of the power generation industry. For this reason, a thorough examination of the aerodynamic rotor performance of a modern large-scale wind turbine working on existing onshore wind farms is critically important to monitor and control the turbine performance and also for forecasting turbine power. This study focuses on the aerodynamic rotor performance of a 3300-kW modern commercial large-scale wind turbine operating on an existing onshore wind farm based on the measurement data. First, frequency distributions of wind speeds and directions were obtained using measurements over one year. Then, wind turbine parameter...
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