Gökhan Kirkil

Kirkil, Gökhan

Name Variants

K.,Gokhan
G. Kirkil
Kirkil,Gokhan
Kirkil,G.
GÖKHAN KIRKIL
Kirkil, Gokhan
K., Gokhan
Kirkil, G.
Gökhan KIRKIL
Kirkil G.
Gökhan Kirkil
Gokhan, Kirkil
KIRKIL, Gökhan
K., Gökhan
KIRKIL, GÖKHAN
Kirkil, GÖKHAN
Kirkil, Gökhan
Kirkil, Gökhan
Kirkil, Gökhan

Job Title

Doç. Dr.

Email Address

gokhan.kirkil@khas.edu.tr

Main Affiliation

Civil Engineering

Sustainable Development Goals Report Points

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Scholarly Output

34

Articles

15

Citation Count

358

Supervised Theses

8 Scholarly Output Search Results

Now showing 1 - 10 of 33

Citation - WoS: 0
Flow Structure in a Mixing Layer Developing Over Flat Bed at High Reynolds Numbers
(Iahr-int Assoc Hydro-environment Engineering Research, 2015) Kirkil, Gokhan; Kirkil, Gökhan; Civil Engineering
Results of a high resolution Detached Eddy Simulation (DES) are used to characterize the evolution of a shallow mixing layer developing between two parallel streams in a long open channel with a flat bed at a high Reynolds number (ReD= 160,000). The influence of Reynolds number on the development of the mixing layer as well as the vertical nonuniformity in the mixing layer structure is discussed. The numerical results show that as Reynolds number increases, the mixing layer development ceases earlier. Mixing layer growth rate and its change in the vertical direction at ReD= 160,000 are compared with experiments and a simulation at ReD= 16,000. Passive scalar is introduced at the tip of the splitter plate close to the free surface to estimate the size of the mixing structures based on mass transport. The effect of the Reynolds number on the shift of the centerline of the mixing layer is quantified.
Citation - WoS: 30
Citation - Scopus: 37
Turkish Public Preferences for Energy
(Elsevier Science, 2018) Ediger, Volkan S.; Kirkil, Gökhan; Kirkil, Gökhan; Ediger, Şevket Volkan; Çelebi, Emre; Ucal, Meltem; Ucal, Meltem Şengün; Kentmen-Cin, Çiğdem; Economics; Industrial Engineering; Civil Engineering
Public concern over energy supplies prices sustainability and efficiency has emerged as a major issue around the world. Yet most of what we know regarding public opinion on energy comes from North America and Europe. This paper presents the results from the 2016 Turkish Public Preferences for Energy Survey which included 1204 respondents and examined Turkish residents' household energy consumption energy policy preferences and environmental concerns. The main findings were that Turkish citizens consider natural gas and electricity highly expensive view dependence on imported energy as Turkey's most pressing energy challenge and recognize the problem of climate change. This lends public support for wind and solar power but at the same time energy issues and the environment policies of political parties do not affect voting choices and political preferences.
Citation - WoS: 0
A Numerical Study of Shallow Mixing Development Over Flat Surface and Dunes
(TSINGHUA UNIV, 2013) Kirkil, Gökhan; Kirkil, Gökhan; Constantinescu, George; Civil Engineering
Results of a high resolution Detached Eddy Simulation (DES) are used to characterize the evolution of a shallow mixing layer developing between two parallel streams in a long open channel with a smooth flat bed and dunes. The study discusses the vertical non-uniformity in the mixing layer structure and provides a quantitative characterization of the growth of the large-scale quasi two-dimensional (2D) coherent structures with the distance from the splitter plate. Results show that in streamwise sections situated between 75D (D is the channel depth) and 150D from the splitter plate the width of the mixing layer close to the free surface is 20-30% more than the width in the near-bed region in the case in which the channel bed is flat. This is mostly because of the tilting of the mixing layer interface on the low-speed side toward the low speed stream as the free surface is approached. Power spectra of the horizontal velocity components show the presence of a -3 subrange at streamwise locations situated more than 10D from the splitter plate consistent with the presence of large-scale quasi 2D horizontal eddies and the transfer of energy (inverse energy cascade) from the smaller scales toward these eddies. Consistent with visualizations of the mass transport of a passive scalar within the mixing layer close to the free surface the estimated streamwise length of the quasi 2D mixing layer eddies is about 2.5 to 3.0 times larger than the local width of the mixing layer. The presence of large-scale roughness elements in the form of an array of two-dimensional dunes with a maximum height of 0.25D (D is the channel depth) induces a much more rapid and larger shift of the centerline of the mixing layer due to the increased influence of the bottom roughness.
Decarbonization Potentials in the Turkish Energy Intensive Industries
(Kadir Has Üniversitesi, 2021) Ünlü, Begüm; Kirkil, Gökhan; Kirkil, Gökhan; Civil Engineering
Biyoçeşitlilik ve iklim krizi ile mücadelede uluslararası kuruluşların önderliğinde küresel ısınmayı minimumda tutmak üzere bir dizi önlem alınmaktadır. Önlemlerden biri olan sera gazı emisyonlarının azaltılması için öncelikle enerji sektöründe yoğun karbonlu kaynaklardan düşük karbonlulara geçiş sağlanmaktadır. Lakin sadece enerji geçişinin emisyonları azaltmak için yeterli olmadığı bilinmektedir. Bu nedenle küresel emisyon salınımında enerjiden sonra ikinci sırada gelen sanayi sektöründe karbonsuzlaştırma yöntemlerine ağırlık verilmektedir. Çoğu gelişmiş ülkenin çalışmalarında Enerji Yoğun Endüstri olarak sınıflandırılan, üretim sürecinde yoğun enerji harcayan ve yoğun emisyona sebep olan alt sektörlere özel karbonsuzlaştırma önerileri kapsamlı bir şekilde ele alınmaktadır. Türkiye Sanayisi ise teknolojik araştırma ve geliştirmeleri enerji verimliliğine odaklanarak gerçekleştirmektedir. Karbonsuzlaştırma seçenekleri enerji verimliliğini de içine alan geniş bir yelpaze sunduğu için Türk Sanayisi tarafından da benimsenmelidir. Bu çalışma Türkiye'de üretim yapan enerji yoğun endüstrilerde karbonsuzlaştırma potansiyelini sunmayı amaçlamıştır. Çalışmada öncelikle karbonsuzlaştırma kavramı ve iklim krizi ile mücadalede ön saflarda yer alan uluslarası kuruluşların karbonsuzlaştırmaya bakış açısı incelenmiştir. Ardından küresel çapta uygulanan karbonsuzlaştırma seçenekleri araştırılıp enerji yoğun endüstrilere özel çözümler saptanmıştır. Daha sonra Türkiye'de enerji yoğun endüstriler alt sektör bazında incelenmiş ve uygun olan karbonsuzlaştırma önerileri sunulmuştur. Bu önerilerin hayata geçmesi için hükümetin, kuruluş ve sanayicilerin iklim krizi ile mücadelede küresel hedeflere uygun, ortak bir yaklaşım benimsemesi gerekmektedir. Ancak bu sayede sanayide karbonsuzlaştırma seçeneklerinin değerlendirilmesi mümkün olabilecektir.
Citation - Scopus: 1
Genesys-Mod Turkey: Quantitative Scenarios for Low Carbon Futures of the Turkish Energy System
(IEEE Computer Society, 2022) Hasturk, I.S.; Kirkil, Gökhan; Celebi, E.; Yucekaya, A.D.; Kirkil, G.; Civil Engineering
This paper examines the quantitative scenarios for low-carbon futures of the Turkish energy system at aggregated (country level) and regionally disaggregated (NUTS-1 level) levels. We have employed four different storylines for the future European energy system. They are quantified and implemented for the European energy system (30 regions, mostly single countries, including Turkey) using the open-source global energy system model, GENeSYS-MOD v3.0. We have compared the results of all scenarios at aggregated and disaggregated levels and found that there are significant differences among them. Specifically, the hydrogen production (and its use) has increased considerably in the disaggregated model when compared to the aggregated level results. The major reason for these differences is found to be the better estimation of regional renewable capacity factors (wind and solar) in the disaggregated level compared to aggregated level. © 2022 IEEE.
Energy Transition Scenario Analysis for Turkey Using Long Range Energy Alternatives Planning (leap)
(Kadir Has Üniversitesi, 2019) Massaga, Daniel Julius; Kirkil, Gökhan; Kirkil, Gökhan; Civil Engineering
Fossil fuel thermal power plants constitute a large part of the Turkish electricity generation capacity. The Turkish government has been developing several energy policy documents to evaluate how various renewable energy sources of the country can be utilized optimally in the generation of electricity for the next 30 years. The study considers three scenarios in the transition to renewable energy for Turkey; the business as usual (BAU), energy conservation (EE) and renewable energy (REN) scenarios were modeled with the help of the LEAP (Long-range Energy Alternatives Planning) software. EE scenario considers the use of energy-efficient appliances across all sectors of demand while emphasizing on more efficiency in electricity production activities, whereas REN scenario considers increasing the share of the renewable energy sources as much as possible in the power generation mix. These scenarios were evaluated in terms of cost and environmental impact. The optimized energy efficiency scenario has been shown to be the optimal energy policy option for Turkey in terms of cost and environmental impact. Keywords: renewable energy, energy transition, energy efficiency, LEAP, scenario analysis
Citation - WoS: 0
Citation - Scopus: 0
The Role of Hydrogen in the Energy Mix: a Scenario Analysis for Turkey Using Osemosys
(Mdpi, 2024) Kirkil, Gökhan; Kirkil, Gokhan; Civil Engineering
The urgent need to tackle climate change drives the research on new technologies to help the transition of energy systems. Hydrogen is under significant consideration by many countries as a means to reach zero-carbon goals. Turkey has also started to develop hydrogen projects. In this study, the role of hydrogen in Turkey's energy system is assessed through energy modeling using the cost optimization analytical tool, Open Source Energy Modelling System (OSeMOSYS). The potential effects of hydrogen blending into the natural gas network in the Turkish energy system have been displayed by scenario development. The hydrogen is produced via electrolysis using renewable electricity. As a result, by using hydrogen, a significant reduction in carbon dioxide emissions was observed; however, the accumulated capital investment value increased. Furthermore, it was shown that hydrogen has the potential to reduce Turkey's energy import dependency by decreasing natural gas demand.
The Renewable Energy Transition in Turkey
(Kadir Has Üniversitesi, 2019) Yılmaz, Mesut Can; Kirkil, Gökhan; Ediger, Volkan S.; Kirkil, Gökhan; Civil Engineering
Energy is an integral part of human life. The energy demand has been increasing for many years. The primary energy source differed over time. Fossil fuels dominated the energy market since 19th century. Overuse of fossil fuels has created serious problems such as climate change. In order to tackle these problems renewable energy source (RES) utilization gained importance in the recent years. With the help of economic and technological improvements, the transition from fossil fuels to renewables has accelerated in recent decades. Many countries have already started to invest in RES instead of fossil fuels. Germany and China have some unique characteristics that can help to reshape Turkey's roadmap to the renewables. Turkey is a developing country with a population of about 80 million. Turkey's energy import dependency is 77%. According to the experts, Turkey has a good potential for RES. Due to its geographical position there is adequate potential of solar, wind, hydro and geothermal. Turkey has an opportunity to utilize its RES potential. If the important steps are taken, RES can become the primary source of Turkey's energy demand and would have positive effects on both the economy and sustainability. Key words: Renewable Energy Transition, Sustainability, Solar, Wind, Climate Change, Carbon Emissions
Citation - WoS: 0
Citation - Scopus: 0
Superior Conductivity of Transparent Zno/Mos_{2< Composite Films for Optoelectronic and Solar Cell Applications}
(Mdpi, 2023) Tareq, Shahad; Kirkil, Gökhan; Kirkil, Gokhan; OEzugur Uysal, Bengue; Civil Engineering
The use of transparent conductive oxides in optoelectronics created a revolution where new-generation materials with high transmittance, low sheet resistance values, durability, and portability can be achieved without decreasing efficiency or increasing costs. Transparent ZnO/MoS2 sandwich-structured conductive composite films were produced in this study via the sol-gel method, which is considered the most efficient method due to its simple process and low cost. The crystal structure properties of ZnO/MoS2 were characterized via X-ray diffraction (XRD) patterns. The crystal sizes of ZnO films doped with different amounts of MoS2 were determined. A UV-visible absorption spectrometer was used to perform the spectroscopic analysis of the film. The area under the absorption curve and the full width of the half-maxima of absorbance data were calculated. Using these values, the optimum amount of MoS2 was determined for the best additive distribution. In addition, in order to determine the best transparent conductive material, resistance values measured via the four-point probe method were compared for different MoS2 additive amounts. The optical and electrical characterizations of transparent ZnO/MoS2 conductive oxide films were investigated. According to the parameters obtained via UV-vis spectroscopy, XRD, and four-point probe measurements, the most effective dispersion that exhibits a low width ratio and high resonance ratio was found for ZnO/MoS2 with a doping amount of 4 mg, the crystallite size of the films was found to be within the range of 21.5 and 24.6 nm, and these observations demonstrated a figure-of-merit value of more than 4.8 x 10(-2) with respect to these sandwich-structured films. Compared to the values of previous studies on various transparent ZnO-doped conductive oxide materials, it is possible to claim that these new films have a structure that is very similar to the transparent conductivity characteristics of other films, and they may even be superior relative to some MoS2 amounts.
Importance of Lng in Turkish Natural Gas Supply Security
(Kadir Has Üniversitesi, 2019) Alkan, Mehmet Batuhan; Kirkil, Gökhan; Ediger, Volkan S.; Kirkil, Gökhan; Civil Engineering
The Natural Gas has been increasing its share of usage day by day due to the technologic developments, low carbon emission, increasing natural gas reserve in the fossil-based energy market. Nowadays, the share of natural gas in the total energy mix is 24%. Hence, the natural gas has been seen as a transaction source because the countries are in the aim of zero carbon emission. LNG is the most increasing product in the natural gas market these days due to shale gas production areas are far away to consumption areas according to this LNG usage has increased. LNG has been increased usage areas of natural gas and secure countries natural gas supply with regard to flexible system integration, easy transportation, and small scale cargos like oil products. Furthermore, LNG is an essential value for Turkish natural gas market. In this study, the importance of LNG in Turkish natural gas supply security has examined. First of all, world natural gas and LNG market have analyzed, and developments and changes on the market have reviewed. Following to this, the Turkish natural gas market has been analyzed and business opportunities which LNG may make and advantages to the market have searched. In the mathematical model, future natural gas consumption, a share of LNG and pipe gas has been forecasted with three different scenarios. According to these forecasts, the determination has made with regard to the storage investments and what has to be done. Finally, what LNG is going to gain to the Turkish market and the importance of LNG in the Turkish natural gas supply is underlined. Keywords: LNG, Natural Gas, Supply Security, importance of LNG