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Impact of the local flexible membrane (LFM) on aerodynamic phenomena including the formation of a laminar separation bubble (LSB) and transition to turbulence was experimentally investigated over the suction surface of a Clark-Y airfoil first time in literature. The experiments such as aerodynamic force measurement, smoke-wire flow visualization and hot-film tests were carried out at the free-stream velocity of U infinity = 3.2 m/s, U infinity = 6.4 m/s, U infinity = 9.6 m/s, U infinity = 12.8 m/s, and Reynolds number based upon on the chord length was Rec = 3.5 x 104, Rec = 7.0 x 104, Rec = 1.05 x 105 and Rec = 1.4 x 105, respectively. The experimental angle of attack was set at 0 degrees = alpha

Energy consumption which is the most critical input in daily life is increasing constantly because of the growth of the world population and development of the devices. The transportation industry which is responsible for almost half of all worldwide emissions is switching to innovative devices run on renewable energy. Renewable-powered charging stations are important for reducing the environmental impact of vehicles. The objective of the study was to determine the best hydrogen charge station locations and rates which are supplied by coupled solar power plants. The GIS-based assessment was carried out with proper data from data sources such as Copernicus Land Monitoring (CLC 2018), and Global Solar Atlas (GSA). For the determination of suitable regions for solar power plants, eight sub-criteria were assessed under technical (C1), accessibility (C2), and environmental (C3) main criteria. Afterward, the obtained result map layer and suitability of the six determined water bodies, located in the study region, were investigated by assuming the buffer zone value. Results showed that the study area had suitable regions of 38.1km2indicating that %22.4 of it was convenient for the solar power plant investments. While Cihanbeyli Lake does not have the highest suitable region, the biggest suitable area inside the buffer zone of lakes was determined as the Ağcaşayar Dam. The maximum annual solar production level is obtained as 1,919 MWh/year in the Ağcaşayar Dam, with a hydrogen production of 34,933 tons/year. Consequently, the Ağcaşayar Dam is the best suitable destination for a hydrogen fuel station in Kayseri.

A passive flow control device with a local flexible membrane material over the suction surface was experimentally investigated with a smoke-wire experiment and time-dependent force measurement in this study. The experiments were performed on both the uncontrolled and the controlled FX 84-W-150 wind turbine airfoils applying the local flexible membrane at different locations first in the literature. The smoke-wire result for the uncontrolled airfoil indicated that a laminar separation bubble formed over the suction surface and the increasing incidence caused the short bubble at lower angles of attack to turn into the long bubble at moderate angles of attack by shifting upstream. After the experiment for the uncontrolled airfoil, six different locations of local flexibility were considered on the suction surface. All tests showed that applying the local flexibility especially at the leading edge ensured better aerodynamic performance. Additionally, it was observed that the lift coefficient was negatively affected when the length of local flexibility increased. As a result of these findings, employing the local flexibility between x/c = 0.2 and x/c = 0.4 over the suction surface was determined as the best optimum location and length. With employing this configuration, the laminar separation bubble was not only suppressed and eliminated but the fluctuations of the lift and the drag curves especially at moderate incidences were also decreased, resulting in increasing in aerodynamic performance as well as having less vibration and more stable on wind turbine airfoil. Apart from the studies regarding wind turbine airfoils with the local flexible material in the literature, our results bear witness that mounting this passive flow controller close to the leading edge and keeping it shorter was more influential in terms of the power output of wind turbine blades. (c) 2021 Elsevier Ltd. All rights reserved.

This study was conducted to determine the milk yield and reproduction characteristics, genetic trend, and breeding values of Holstein cattle reared in Teke region (Antalya, Burdur, Denizli, and Isparta provinces) of Turkey. In this study, 9844 lactation and reproductive records of Holstein Friesian dairy cattle for the period of 2010 to 2017 were used. For this purpose, variance components and the heritability were calculated based on calving interval (CI) and number of inseminations per conception (NIC) from fertility characteristics and lactation length (LL), 305-day milk yield (305 DMY), and dry period (DP). It was determined that CI, NIC, LL, 305 DMY, and DP were 0.11, 0.10, 0.11, 0.33, and 0.01, respectively. The genetic trend of 305 DMY was 111.5 kg/year. The average breeding value was negative between 2005 and 2009 and positive between 2010 and 2015. In conclusion, the fact that especially 305 DMY heritability was generally higher in this study than the values reported by other studies conducted in Turkey and the genetic trend for 305 DMY was positive and high indicates that breeding value of Holstein cattle in the Teke region is high. Therefore, it can be recommended to continue the pedigree breeding of Holstein cattle in this region, keep pedigree and yield records meticulously, estimate breeding values for selecting animals with superior yield characteristics and using them in future generations, and include current biotechnological methods in breeding program to increase the efficiency in selection. © 2021, The Author(s), under exclusive licence to Springer Nature B.V.

Offshore wind energy resources are not fully exploited renewable energy resources until now and could play a crucial role in mitigating the impacts of climate change by the generation of renewable electricity. Planning processes such as technical, social, environmental, various agents, and political concerns are necessary for the development of offshore wind energy projects. The objective of this study was to assess the comprehensive feasibility of a desired offshore wind power plant applying Geographical Information Systems (GIS) and Multi-Criteria Decision-Making (MCDM) guidance for the coastal area of Turkey. Furthermore, EMODnet (the European Marine Observation and Data Network) was employed for data acquisition to unlock fragmented and hidden marine data resources and to facilitate investment in sustainable coastal and offshore activities. For the determination of potential site with Multi-Criteria Decision Maker Method, 3 main criteria Technical (C1), Environmental (C2), and Social (C3), and 13 sub-criteria were determined. Based on these criteria, the suitability map was created by using all criteria map layers with their buffer zones. The final map indicated that %1.38 (3294.8 km(2)) of Turkey Seas was suitable for offshore wind farms. The most suitable region was determined in the Marmara Sea with 1194 km(2). The Aegean Sea, the Black Sea, and the Mediterranean Sea were following the Marmara Sea in terms of the huge suitable regions respectively. It was apparent that the growth of offshore wind farms in Turkey would increase if the supporting mechanism and the necessary legislation were ensured.

Purpose Wind turbines are one of the best candidates to solve the problem of increasing energy demand in the world. The aim of this paper is to apply a multi-objective structural optimization study to a Phase II wind turbine blade produced by the National Renewable Energy Laboratory to obtain a more efficient small-scale wind turbine. Design/methodology/approach To solve this structural optimization problem, a new Non-Dominated Sorting Genetic Algorithm (NSGA-II) was performed. In the optimization study, the objective function was on minimization of mass and cost of the blade, and design parameters were composite material type and spar cap layer number. Design constraints were deformation, strain, stress, natural frequency and failure criteria. ANSYS Composite PrepPost (ACP) module was used to model the composite materials of the blade. Moreover, fluid–structure interaction (FSI) model in ANSYS was used to carry out flow and structural analysis on the blade. Findings As a result, a new original blade was designed using the multi-objective structural optimization study which has been adapted for aerodynamic optimization, the NSGA-II algorithm and FSI. The mass of three selected optimized blades using carbon composite decreased as much as 6.6%, 11.9% and 14.3%, respectively, while their costs increased by 23.1%, 29.9% and 38.3%. This multi-objective structural optimization-based study indicates that the composite configuration of the blade could be altered to reach the desired weight and cost for production. Originality/value ACP module is a novel and advanced composite modeling technique. This study is a novel study to present the NSGA-II algorithm, which has been adapted for aerodynamic optimization, together with the FSI. Unlike other studies, complex composite layup, fiber directions and layer orientations were defined by using the ACP module, and the composite blade analyzed both aerodynamic pressure and structural design using ACP and FSI modules together.

Rüzgar enerjisi çevre dostu, karlı ve yenilenebilir bir enerji kaynağıdır. Rüzgar enerjisi yayılımı son yirmi yılda artmaktadır. Bu çalışmada, deniz üstü rüzgar yayılımı potansiyeli olan Bandırma körfezi içindeki en uygun alanın belirlenmesi için çalışılmış ve sonuç olarak buradaki potansiyel deniz üstü güç kapasitesi tahmin dilmiştir. Bu çalışma, görsel ve hızlı analiz sonuçlarını elde etmek için Coğrafi Bilgi Sistemi ve Çok-Kriterli-Karar-Verme Metodolojisi metodlarını birlikte kullanmaktadır. Bu kapsamda rüzgar hızı, deniz derinliği, kuş göç hatları gibi sekiz standart kriter uygulanarak detaylı bir şekilde Coğrafi Bilgi Sistemi kullanılarak incelenmektedir. Bandırma'nın deniz trafiği yoğunluğunun yüksek olması nedeniyle uygun bölge seçiminde gemi rotaları önemli ölçüde rol oynarken, askeri bölgelere, haberleşme kablolarına ve turistik alanlara yakınlık uygun bölge seçiminde sonucu etkileyecek derecede değildir. Sonuç olarak, denizüstü rüzgar santrali kurulumu için iki konum uygun olarak bulunmuştur; biri kuzeybatıda, diğeri ise Bandırma körfezininkuzey doğusunda, sırasıyla 72 MW ve 48 MW kapasitelidir., Wind energy is an environmentally friendly, profitable, and renewable energy resource. Wind energy eployment is increasing in the last two decades. In this paper, Bandırma bay which has a potential for offshore wind deployment is studied to determine the most suitable area in it and eventually potential offshore power capacity of the location is estimated. This study combines applications of Geographical Information System and Multi-Criteria- Decision-Making Methodology to obtain fast results supported with visual documentation. In this scope, eight standard criteria such as wind speed, water depth, bird migration lines are applied and nvestigated in detail by using Geographical Information System. It is found that there is sufficient wind speed t the shallow level of the sea. Consequently, two locations are found to be suitable; one is on the northwest and the other one is on the north east of Bandırma, with capacities of 72 MW and 48 MW, respectively.

Purpose The purpose of this exhaustive experimental study is to investigate the fluid-structure interaction in the flexible membrane wings over a range of angles of attack for various Reynolds numbers. Design/methodology/approach In this paper, an experimental study on fluid-structure interaction of flexible membrane wings was presented at Reynolds numbers of 2.5 × 104, 5 × 104 and 7.5 × 104. In the experimental studies, flow visualization, velocity and deformation measurements for flexible membrane wings were performed by the smoke-wire technique, multichannel constant temperature anemometer and digital image correlation system, respectively. All experimental results were combined and fluid-structure interaction was discussed. Findings In the flexible wings with the higher aspect ratio, higher vibration modes were noticed because the leading-edge separation was dominant at lower angles of attack. As both Reynolds number and the aspect ratio increased, the maximum membrane deformations increased and the vibrations became visible, secondary vibration modes were observed with growing the leading-edge vortices at moderate angles of attack. Moreover, in the graphs of the spectral analysis of the membrane displacement and the velocity; the dominant frequencies coincided because of the interaction of the flow over the wings and the membrane deformations. Originality/value Unlike available literature, obtained results were presented comparatively using the sketches of the smoke-wire photographs with deformation measurement or turbulence statistics from the velocity measurements. In this study, fluid-structure interaction and leading-edge vortices of membrane wings were investigated in detail with increasing both Reynolds number and the aspect ratio.

In this study, to analyze the mtDNA D-loop region and the origin of the maternal lineages of 16 different donkey populations, and to assess the domestication of Turkish indigenous donkeys in seven geographical regions, we investigated the DNA sequences of the D-loop region of 315 indigenous donkeys from Turkey. A total of 54 haplotypes, resulting from 35 polymorphic regions (27 parsimoniously informative and 6 singleton sites), were defined. Twenty-eight of these haplotypes are unique (51.85%), and 26 are shared among different Turkish indigenous donkey populations. The most frequent haplotype was Hap 1 (45.71%), followed by two haplotypes (Hap 4, 15.55% and Hap 7, 5.39%). The breed genetic diversity, evaluated by the haplotype diversity (HD) and nucleotide diversity (&pi, D), for the Turkish donkey populations ranged from 0.533 &plusmn, 0.180 (Tekirdağ&ndash, Malkara, MAL) to 0.933 &plusmn, 0.122 (Aydin, AYD), and from 0.01196 &plusmn, 0.0026 (Antalya, ANT) to 0.02101 &plusmn, 0.0041 (Aydin, AYD), respectively. We observed moderate-to-high levels of haplotype diversity and moderate nucleotide diversity, indicating plentiful genetic diversity in all of the Turkish indigenous donkey populations. Phylogenetic analysis (NJT) and median-joining network analysis established that all haplotypes were distinctly grouped into two major haplogroups. The results of AMOVA analyses, based on geographic structuring of Turkish native donkey populations, highlighted that the majority of the observed variance is due to differences among samples within populations. The observed differences between groups were found to be statistically significant. Comparison among Turkish indigenous donkey mtDNA D-loop regions and haplotypes, and different countries&rsquo, donkey breeds and wild asses, identified two clades and which is named Somali (Clade IV) and Nubian (Clade V) lineages. The results can be used to understand the origin of Turkish donkey populations clearly, and to resolve the phylogenetic relationship among all of the different regions.

Over the past years, the installations of Shallow Geothermal Energy (SGE) systems are increasing throughout Europe, and it is indicating that a specific and detailed legal framework is necessary. Towards this direction, this paper consists of an overview of legislation issues on SGE at European level, based on concise reviews from fourteen countries, i.e., Croatia, Cyprus, France, Greece, Italy, Latvia, Lithuania, Poland, Portugal, Serbia, Slovenia, Spain, Sweden, and Turkey. Said reviews discuss key national legislation as well as experts’ experience in the procedure of SGE integration. Legal and technical issues are also critically discussed for all involved countries, both individually and collectively. Findings show that high diversity exists on legislation provisions as well as on regulations, standards, and institutional support amongst European countries. The latter acts as an effective barrier for the further development of the SGE market ; therefore indicating the need for a common approach. Increase of awareness, need for standardization, improvement of legal framework, and administration procedures and permitting, are essential steps in moving forward and supporting the effectiveness of design, construction, maintenance, and operation of SGE systems.

Humpback whales have very special fins, which reduce the friction force by the projections on the fins and enhance the lift force with increasing angle of attack. Thus, it has opportunity to move with less energy. In this study, the tubular structure was formed and adapted to the NACA0012 airfoil profile. Numerical modelling of tubercle wing was performed in ANSYS FLUENT. In numerical modelling, k-ω SST and Transition SST turbulence models were used to investigate tubercle wing performance. The tubercle structure on the wing provided to canalize the flow in the tubercle cavities, thus flow separation decreased. Consequently, it was observed that the aerodynamic performance of the wing increased when the sinusoidal protrusions known as tubercle structure were applied to the leading edge of the wing.

The proposal of this paper is clear to reveal and understand the unsteady flow characteristics over the surface of chambered airfoil operating especially at low Reynolds numbers by detecting boundary layer separation and laminar separation bubble (LSB). Experiments including smoke-wire technique for flow visualization, velocity measurement via hot-wire sensor and quasi-wall shear stress measurement by means of the hot-film sensor have been performed over the suction surface of NACA 4412 airfoil at Reynolds number of 5x104 and angle of attack of 14°. Experiments indicate that the airfoil at a stall angle exhibits the bistable characteristics over the suction surface because of the unsteady bubble bursting at low Reynolds numbers. That is, either laminar flow separates from the leading-edge of the airfoil owing to a dominant adverse pressure gradient (APG) or it does not separate along downstream. It is also noted that unsteady boundary layer formation may affect the flow characteristics by changing airfoil’s stability appreciably, causing the periodic fluctuations with the occurring bubble bursting and the leading edge and trailing edge vortex merging. This may conclude undesirable problems such as noise, vibration and flutter for the flight vehicles and wind turbines.

In this experimental study, flow over NACA 4412 airfoil with flexible membrane mounted both on suction surface and pressure surface was investigated at Reynolds number of 5x104 and different angles of attack. The smoke-wire visualization method was used for flow visualization to demonstrate flow phenomena as laminar separation bubble (LSB), leading edge separation and tip vortices. A constant temperature anemometer (CTA) was used for measuring flow over the partially flexible airfoil. Concerning the flow visualization, smoke-wire experiment was been conducted at z/c=0.1 and z/c=0.4. Besides, hot-wire experiment by means of CTA was employed to measure flow properties including values of velocity, turbulence statistics and Reynold stress over both uncontrolled and controlled airfoil. The results showed that partially flexible airfoil had several benefits compared with the uncontrolled airfoil. The results for this partially flexible airfoil were mainly lower size of LSB, higher stall angle of attack, ensuring more stable flow characteristics and more aerodynamic performance.

In the current study, the aerodynamic performance of NACA 4412 airfoil with sandpaper which was used as an alternative control device instead of vortex generators was investigated. It was especially considered how the sandpaper affected the growth of the separation bubble. Regarding the flow visualization, the smoke-wire experiment was done at different angles of attack and Reynolds numbers. Moreover, the hot-wire experiment was employed to measure velocity as well as the values of the turbulence statistics over and near wake of the airfoil. Besides the mentioned experiments, the force measurement was performed to obtain aerodynamic forces, and quasi-wall shear stress was measured by means of a hot-film sensor. With the roughness, the instability in the long transition region at low Reynolds number was bypassed. Flow momentum was increased in the boundary layer on the airfoil surface, and the flow over the roughened airfoil exhibited more resistance against adverse pressure gradients. The flow triggered by the roughness element suppressed the bubble, which meant pre-stall flow control carried out with resulting CL increment and CD reduction. Finally, using the sandpaper over the airfoil provided prominent benefits in terms of postponing of the stall and enhancement of aerodynamic performance for wind turbine blades.

In present study, aerodynamics of a NACA4412 wings with aspect ratio of 1 and 3 was considered experimentally at Reynolds numbers of 2.5 × 104, 5 × 104 and 7.5 × 104. Studies for AR = 1 wing showed that stall was delayed and extra (vortex) lift was obtained, because separation bubble got smaller in both chordwise and spanwise axes with effect of wing-tip vortices. Oil-flow experiments at higher angles of attack clarified the reason for vortex lift obtained from AR = 1 wing. However, there was an increase in drag coefficient as well as vortex lift, and stall delayed due to tip vortex. Turbulence intensity distributions pointed out location of the transition to turbulence; Reynolds stress and turbulence kinetic energy distributions indicated shear layer. Furthermore, in experiments of AR = 3 wing, the viscous forces and leading edge vortices were effective at Re = 2.5 × 104 and Re = 5 × 104, but flow over the wing at Re = 7.5 × 104 acted as a 2D flow. After α = 12°, bubble burst and stall consisted abruptly because effectiveness of 3D flow decreased over wing. Strouhal (St) numbers of vortex shedding frequencies in wake of AR = 3 wing had a certain difference from St = 0.17/sinα curve at lower angle of attack (α = 0° − 10°) due to separation bubble, but AR = 1 wings showed that St numbers were near St = 0.17/sinα curve.

WOS: 000417891400002 This study compared the growth curve models for the live weight and body length of Japanese quail raised under lights of various colors. The Brody, Gompertz, and von Bertalanffy growth models were used to investigate the effect of different colored lights on Japanese quail growth over a period of six weeks (1-42 days). Four lights of different colors, comprising yellow, red, blue, and white, were used in the study. According to the different light colors, the mean and standard error for the live weight and body length on day 42 were calculated as 196.09 and 3.87 g and 29.48 and 0.192 cm, respectively. Furthermore, while the differences in live weight according to the color of the light being used were statistically significant on days 14, 21, and 28, there were significant differences in body length on days 7, 28, 35, and 42, depending on the color of the light used. The highest values of R-2 for body length and live weight were 0.9935 and 0.9988; the lowest sum of square error values for body length and live weight were 9.6588 and 10.6623 according to the Gompertz model. Test results did not reveal autocorrelation among serial data except for those grown under red colored lights.

CAYAN, Huseyin/0000-0001-7731-2967 WOS: 000400881900030 The aim of the study was to identify quails which have different body weight for some production traits such as egg production, egg characteristics, daily feed consumption and feed conversion ratio (FCR). The selection was based on body weight in Japanese quail over two generations using 150 quails (120 female and 30 male). These groups consisted of Low Body Weight (LBW), High Body Weight (HBW) and control. Average body weights for females at the end of five weeks were 182.3 +/- 0.5, 159.5 +/- 0.34, and 141.7 +/- 0.55 for LBW, HBW and control groups respectively. There were significant differences between females and males in body weight across the generations. Significant differences were observed for total egg production and egg width for Group X Generation's interactions. Also, statistically significant differences were found for egg quality parameters such as yolk index, yolk height; yolk diameter, albumin length, and albumin width among generations. As a result, body weight is a very important factor in selection studies and it also increases the efficiency of the selection program with other selection features.

WOS: 000408300200028, In this study, fluid-structure interaction over a flexible membrane wing with aspect ratio (AR) of 3 at low Reynolds numbers was investigated experimentally. Smoke wire flow visualization technique was performed for analyzing time-dependent behavior of flow over this flexible membrane wing. Furthermore, time dependent deformation of flexible membrane wing was measured. It was clearly seen that the value of membrane deformation increased with increasing angle of attack. Moreover, it was stated that the size of laminar separation bubble (LSB) changed with time due to the unsteady flow characteristics of membrane wing. The unsteady behavior over the flexible membrane wing caused different deformation modes to form at different angles of attack. For the flexible wings with higher aspect ratios, the LSB was more dominant in the membrane wings at low Re numbers, and caused the membrane vibration to increase based on the angle of attack which the LSB started to be overpowering. (C) 2017 Elsevier Masson SAS. All rights reserved., Scientific and Technological Research Council of Turkey (TUBITAK) [213M329]; Scientific Research Projects Unit of Erciyes University [FDK-2015-6171, FDA-2014-5273, FBG-2014-5337], The authors would like to thank the Scientific and Technological Research Council of Turkey (TUBITAK) under the project number: 213M329, and the Scientific Research Projects Unit of Erciyes University under the contract numbers: FDK-2015-6171, FDA-2014-5273 and FBG-2014-5337 for funding.

In this study, the effect of perpendicular acoustic excitation on laminar separation bubble, aerodynamic characteristics and stall characteristics over a NACA 2415 aerofoil was investigated experimentally at low Reynolds numbers at varying angles of attack. Extensive experiments such as force and pressure measurements, flow visualization via smoke-wire technique and velocity measurement via hot-wire system were conducted. The experimental results showed that when acoustic excitation of a certain frequency was applied, the length of the laminar separation bubble was shortened owing to the energy added to the flow by acoustic excitation. Because of the shortened laminar separation bubble, coefficient of lift was increased. Furthermore, at the stall angles the separated flow was forced to reattach to the surface of the aerofoil by acoustic forcing, so the stall angle and maximum coefficient of lift were increased, and drag coefficient was decreased.

Bu çalışmada Japon bıldırcınlarında canlı ağırlık ile çeşitli vücut ölçüleri arasındaki ilişkilerin belirlenmesine çalışılmıştır. Bu amaçla deneme hayvanı olarak 72 günlük yaşta bulunan 109 Japon bıldırcınının vücut ölçüleri (mm) (kanat uzunluğu, vücut uzunluğu, ayak uzunluğu, orta parmak uzunluğu, gaga uzunluğu, gaga genişliği, göğüs çevresi ) ve canlı ağırlıkları (g) alınmıştır. Canlı ağırlık ile çeşitli vücut ölçüleri arasındaki ilişkilerin belirlenmesinde ise korelasyon katsayıları ve Temel Bileşenler Analizi (TBA) kullanılarak hayvanların büyüme performansları üzerine olan etkileri araştırılmıştır. İncelenen özellikler bakımından cinsiyet faktörünün etkisi canlı ağırlık ve vücut uzunluğu bakımından önemli bulunmuştur (p

10th Anniversary International Conference on Experimental Fluid Mechanics -- NOV 17-20, 2015 -- Prague, CZECH REPUBLIC, WOS: 000400395300018, In this study, the flow over NACA4412 was investigated both numerically and experimentally at a different Reynolds numbers. The experiments were carried out in a low speed wind tunnel with various angles of attack and different Reynolds numbers (25000 and 50000). Airfoil was manufactured using 3D printer with a various aspect ratios (AR = 1 and AR = 3). Smoke-wire and oil flow visualization methods were used to visualize the surface flow patterns. NACA4412 aerofoil was designed by using SOLIDWORKS. The structural grid of numerical model was constructed by ANSYS ICEM CFD meshing software. Furthermore, ANSYS FLUENTTM software was used to perform numerical calculations. The numerical results were compared with experimental results. Bubble formation was shown in CFD streamlines and smoke-wire experiments at z / c = 0.4. Furthermore, bubble shrunk at z / c = 0.2 by reason of the effects of tip vortices in both numerical and experimental studies. Consequently, it was seen that there was a good agreement between numerical and experimental results., DANTEC Dynam GmbH, LAVISION, LENAM, MECAS ESI s r o, MIT s r o, TSI GmbH, Scientific and Technological Research Council of Turkey (TUBITAK) [213M329], The authors would like to acknowledge funding from the Scientific and Technological Research Council of Turkey (TUBITAK) under the project no: 213M329.

10th Anniversary International Conference on Experimental Fluid Mechanics -- NOV 17-20, 2015 -- Prague, CZECH REPUBLIC, WOS: 000400395300032, In this study, unsteady flow around flexible membrane wing which had aspect ratio of 1 (AR=1) was investigated experimentally at various Reynolds numbers (Re = 25000 and Re = 50000). Smoke-wire technique for flow visualization over the flexible membrane wing was utilized in the experiments. Digital Image Correlation system (DIC) was used for measuring deformation of AR = 1 flexible membrane wing. Instantaneous deformation measurements of membrane wing were combined with the flow field measurements. In low aspect ratio flexible membrane wings, unsteadiness includes tip vortices and vortex shedding, and the combination of tip vortices. In these types of wings, complex unsteady deformations occurred due to vortex shedding. The results showed that the increasing angle of attack results in increase of membrane deformation. Moreover, it was concluded that analysis of the instantaneous deformation revealed chordwise and spanwise, modes which were due to the shedding of leading-edge vortices as well as tip vortices. Consequently, vibrational mode decreased and maximum standard deviation location approached to the trailing edge by reason of increasing angle of attack., DANTEC Dynam GmbH, LAVISION, LENAM, MECAS ESI s r o, MIT s r o, TSI GmbH, Scientific and Technological Research Council of Turkey (TUBITAK) [213M329]; Scientific Research Projects Unit of Erciyes University [FDK-2015-6171, FBG-2014-5337, FDA-2014-5273], The authors would like to acknowledge funding from the Scientific and Technological Research Council of Turkey (TUBITAK) under the project no: 213M329, the Scientific Research Projects Unit of Erciyes University under the contract no: FDK-2015-6171, FBG-2014-5337 and FDA-2014-5273.

It is possible to expose the structure of Ottoman society through the tereke registers which constitute one of the main sources of Ottoman socio-economic history. Analyzing tereke registers is the way to conceptualize the past and to find though static some data respecting the time of their registry. In addition, these registers also provide some information regarding the taste and life styles of people in different levels of Ottoman society. Particularly the preferences for the taste of clothing reflect the statutes and economic power of the people in the society.The purpose of this study is to find out what is the relations between the taste of clothing and the basic necessities of people by analyzing the tereke register of a merchant in Balıkesir in the 19th century. Since the nineteenth century is a period of transformation in Ottoman Empire as is the case all over the world, another aim is to check whether these changes were visible in Balıkesir and to what extent. The answers will be given upon the registry of that Merchant, Hacı Halil. Any change in the taste of clothing between the earlier centuries and the 19th century will be noted according to the registry. Because of this registry we can find out the trade connections, transactions and payment relations among the merchants of Balıkesir. Using this individual’s registry allows us to look at the socio-economic structure of Ottoman society closely.

10th Anniversary International Conference on Experimental Fluid Mechanics -- NOV 17-20, 2015 -- Prague, CZECH REPUBLIC, WOS: 000400395300030, In this study, the effect of the aspect ratio on the aerodynamics characteristic of flexible membrane wings with different aspect ratios (AR = 1 and AR = 3) is experimentally investigated at Reynolds number of 25000. Time accurate measurements of membrane deformation using Digital Image Correlation system (DIC) is carried out while normal forces of the wing will be measured by helping a load-cell system and flow on the wing was visualized by means of smoke wire technic. The characteristics of high aspect ratio wings are shown to be affected by leading edge separation bubbles at low Reynolds number. It is concluded that the camber of membrane wing excites the separated shear layer and this situation increases the lift coefficient relatively more as compared to rigid wings. In membrane wings with low aspect ratio, unsteadiness included tip vortices and vortex shedding, and the combination of tip vortices and vortex shedding causes complex unsteady deformations of these membrane wings. The characteristic of high aspect ratio wings was shown to be affected by leading edge separation bubbles at low Reynolds numbers whereas the deformations of flexible wing with low aspect ratio affected by tip vortices and leading edge separation bubbles., DANTEC Dynam GmbH, LAVISION, LENAM, MECAS ESI s r o, MIT s r o, TSI GmbH, Scientific and Technological Research Council of Turkey (TUBITAK) [213M329]; Scientific Research Projects Unit of Erciyes University [FDK-2015-6171, FBG-2014-5337, FDA-2014-5273], The authors would like to acknowledge funding from the Scientific and Technological Research Council of Turkey (TUBITAK) under the project no: 213M329, the Scientific Research Projects Unit of Erciyes University under the contract no: FDK-2015-6171, FBG-2014-5337 and FDA-2014-5273.

Studies about investigation of hydrogen production from wind energy and hydrogen production costs for a specific region were reviewed in this study and it was shown that these studies were rare in the world, especially in Turkey. Therefore, the costs of hydrogen, hydrogen production quantities using a wind energy conversion system were considered as a case study for 5 different locations of Nigde, Kirsehir, Develi, Sinop and Pinarbasi located in the Central Anatolia in Turkey. Annual wind energy productions and costs for different wind energy conversion systems were calculated for 50 m, 80 m and 100 m hub heights. According to wind energy costs calculations, the amounts and costs of hydrogen production were computed. Furthermore, three different scenarios were taken into account to produce much hydrogen. The results showed that the hydrogen production using a wind energy conversion system with 1300 kW rated power had a range from 1665.24 kgH(2)/year in Nigde at 50 m hub height to 6288.59 kgH(2)/year in Pinarbasi at 100 m hub height. Consequently, Pinarbasi and Sinop have remarkable wind potential and potential of hydrogen production using a wind-electrolyzer energy system. Crown Copyright (C) 2012 Published by Elsevier Ltd. All rights reserved.

This study is a detailed experimental investigation on aerodynamics of a NACA2415 aerofoil by varying angle of attack from -12 degrees to 20 degrees at low Reynolds number flight regimes (0.5 x 10(5) to 3 x 10(5)d). For this investigation, pressure distributions over the aerofoil were measured using a system including a pitotstatic tube, a scanivalve unit and a pressure transducer. Moreover, time-dependant lift and drag forces and pitch moment of the aerofoil were obtained by using an external three-component load-cell system. Velocity measurements at different points over the aerofoil were carried out by using a hot-wire anemometer, and oil flow visualization method was used to photograph the surface flow patterns. The experimental results showed that as the angle of attack increased, the separation and the transition points moved towards the leading edge at all Reynolds numbers. Furthermore as the Reynolds number increased, stall characteristic changed and the mild stall occurred at higher Reynolds numbers whereas the abrupt stall occurred at lower Reynolds numbers. The stall angle varied with Re number due to the viscous effects and decreased with decreasing Re number. By the decreasing of the Re number, short bubble burst at higher angles of attack, which caused long bubble to occur. (C) 2012 Elsevier Inc. All rights reserved., This study is a detailed experimental investigation on aerodynamics of a NACA2415 aerofoil by varying angle of attack from -12° to 20° at low Reynolds number flight regimes (0.5 × 105 to 3 × 105). For this investigation, pressure distributions over the aerofoil were measured using a system including a pitot-static tube, a scanivalve unit and a pressure transducer. Moreover, time-dependant lift and drag forces and pitch moment of the aerofoil were obtained by using an external three-component load-cell system. Velocity measurements at different points over the aerofoil were carried out by using a hot-wire anemometer, and oil flow visualization method was used to photograph the surface flow patterns. The experimental results showed that as the angle of attack increased, the separation and the transition points moved towards the leading edge at all Reynolds numbers. Furthermore as the Reynolds number increased, stall characteristic changed and the mild stall occurred at higher Reynolds numbers whereas the abrupt stall occurred at lower Reynolds numbers. The stall angle varied with Re number due to the viscous effects and decreased with decreasing Re number. By the decreasing of the Re number, short bubble burst at higher angles of attack, which caused long bubble to occur.

‡High altitude long endurance UAV flight regime imposes certain difficult testing conditions for the ground based test facilities, such as low density, low freestream turbulence, high alpha, low-Reynolds, and highsubsonic-Mach numbers. High altitude flight testing would be required to collect actual experimental data at an expense of much higher costs. Computational approach is a viable alternative to support generation of design data base for the laminar and transitional boundary layers at high-subsonic-Mach-numbers. In the present study, a two-equation γ-Reθt correlation-based transition model is further developed to predict some airfoils that are frequently used in the design of UAVs. Firstly, the empirical correlations already validated for low to high Mach number flat plate cases is validated for the thin NACA64A006 airfoil at low subsonic speed and high-Reynolds-number. Secondly, the present methodology is successfully demonstrated for the E387 and SD7037 moderately thick UAV type airfoils in the low-Reynolds and low-subsonic-Mach-number conditions. Finally, the relatively thicker APEX-16 airfoils at high-altitude, low-Reynolds-number conditions for high-subsonic Mach numbers are simulated. Results are compared with the available numerical data in the literature obtained through Reynolds Averaged Navier-Stokes and viscous-inviscid interaction methods using the e N method.

ASME International Mechanical Engineering Congress and Exposition -- NOV 09-15, 2012 -- Houston, TX, WOS: 000350070400183, Main aim of this study is to investigate annual wind power output, annual hydrogen production quantity and hydrogen production cost of wind-hydrogen energy system in the Pinarba i-Kayseri region in Turkey which has remarkable wind potential in the central region of Turkey. Turkish State Meteorological Service (TSMS) measured the value of mean wind speed of Pmarba i. as 3.67 m/s above 10m ground between 2000 and 2006 years. In this study, three different hub heights (50m, 80m and 100m) were considered, and so the measured mean wind speed at 10m was extrapolated to considered heights and annual wind power output was calculated. Four different turbine rated powers (800kW, 900kW, 2000kW and 3000 kW) and two different electrolyser powers (120kW and 40kW) for hydrogen production were assumed. Levelised cost of electricity method was used in order to determine the cost analysis of wind energy and hydrogen production. The results of this study bring out clearly the variation of potential of hydrogen production and cost with wind speed, wind turbine hub height and wind turbine rated power and electrolyser power., ASME

WOS: 000309024700015, In this study, the hydrogen production potential and costs by using wind/electrolysis system in Pinarbasi-Kayseri were considered. In order to evaluate costs and quantities of produced hydrogen, for three different hub heights (50 m, 80 m and 100 m) and two different electrolyzer cases, such as one electrolyzer with rated power of 120 kw (Case-I) and three electrolyzers with rated power of 40 kW (Case-II) were investigated. Levelised cost of electricity method was used in order to determine the cost analysis of wind energy and hydrogen production. The results of calculations brought out that the electricity costs of the wind turbines and hydrogen production costs of the electrolyzers are decreased with the increase of turbine hub height. The maximum hydrogen production quantity was obtained 14192 kgH(2)/year and minimum hydrogen cost was obtained 8.5 $/kgH(2) at 100 m hub height in the Case-II., Scientific Research Projects Unit of Erciyes University [FBY-11-3518], The authors would like to acknowledge funding from the Scientific Research Projects Unit of Erciyes University under the contract no: FBY-11-3518.

Low Reynolds Number Flows and Transition

An experimental study of a low aspect ratio rectangular membrane wing in a wind tunnel was conducted for a Reynolds number range of 2.4 x 10(4)-4.8 x 10(4). Time-accurate measurements of membrane deformation were combined with the flow field measurements. Analysis of the fluctuating deformation reveals chordwise and spanwise modes, which are due to the shedding of leading-edge vortices as well as tip vortices. At higher angles of attack, the second mode in the chordwise direction becomes dominant as the vortex shedding takes place. The dominant frequencies of the membrane vibrations are similar to those of two-dimensional membrane airfoils. Measured frequency of vortex shedding from the low aspect ratio rigid wing suggests that membrane vibrations occur at the natural frequencies close to the harmonics of the wake instabilities. Vortex shedding frequency from rigid wings shows remarkably small effect of aspect ratio even when it is as low as unity. (C) 2011 Elsevier Ltd. All rights reserved., An experimental study of a low aspect ratio rectangular membrane wing in a wind tunnel was conducted for a Reynolds number range of 2.4×104–4.8×104. Time-accurate measurements of membrane deformation were combined with the flow field measurements. Analysis of the fluctuating deformation reveals chordwise and spanwise modes, which are due to the shedding of leading-edge vortices as well as tip vortices. At higher angles of attack, the second mode in the chordwise direction becomes dominant as the vortex shedding takes place. The dominant frequencies of the membrane vibrations are similar to those of two-dimensional membrane airfoils. Measured frequency of vortex shedding from the low aspect ratio rigid wing suggests that membrane vibrations occur at the natural frequencies close to the harmonics of the wake instabilities. Vortex shedding frequency from rigid wings shows remarkably small effect of aspect ratio even when it is as low as unity.

Transition-sensitive, single point eddy viscosity models are fairly new and performance assessment of these models is required. In this study, the performance of transition and turbulence models is first evaluated for predicting low Re number flows having laminar separation bubbles that are traditionally quite difficult to predict for RANS-based CFD methods. Second, suppression of the laminar separation bubbles using blowing and/or suction is investigated for a single aerofoil. A prior experimental study using hot-wire anemometry for a clean (no jet) NACA 2415 aerofoil at alpha = 8 degrees at a Reynolds number of 2 x 10(5) shows the presence of a laminar separation bubble. For this flow, the recently developed k-k(L)-omega transition model is first shown to accurately predict the location and extent of the experimentally measured separation bubble. Following this, the same transition model was used to predict the flow over the NACA 2415 aerofoil using single or simultaneous blowing or suction. In the single blowing or suction cases, the separation bubble is not completely eliminated, but either abated or moved downstream. Smaller blowing velocity ratios cause more effective suppression of the separation bubble than larger blowing ratios, independent of the blowing locations. In contrast, larger suction velocity ratios are better than smaller suction ratios for the suppression. Moreover, the lift/drag ratios increase as the jet location moves from the leading edge to a downstream direction in both cases. In the simultaneous blowing and suction cases, the k-k(L)-omega transition model is shown to suppress the separation bubble by using a mix of jet parameters which result in increased lift/drag ratios. Crown Copyright (C) 2010 Published by Elsevier Masson SAS. All rights reserved.