Coskun Ozalp

Osmaniye Korkut Ata university · Energy Systems Engineering

This study investigated flow characteristics and heat transfer properties simultaneously around a heated circular cylinder vertically immersed in a water channel at different Reynolds (Re) numbers. The channel water temperature and heat flow were kept constant during the experiments. The results included time-averaged vorticity contours (<ω>), stre...

Making modifications to a cylinder is one of the most effective ways to change the flow in the cylinder wake region. This study aimed to investigate experimentally and numerically the flow structure of the wake region of a smooth cylinder and rectangular grooved cylinders (roughness coefficients are ϵ/D = 0.02, 0.04, and 0.06, ϵ is the roughness he...

This study investigated the effect of a clockwise and counter-clockwise oscillating (control) cylinder on the flow structure and heat transfer on a heated (bare) cylinder placed in the downstream region of the flow experimentally. In this regard, temperature measurements were made regularly for heat transfer analysis. Particle image velocimetry (PI...

Küp şeklindeki cisimlerin birbiri ile konumlandırılması cisimlerin etrafındaki akış yapısından kaynaklanan akış etkileri açısından önemlidir. Cisimlerin yerleşimi faydalı rüzgâr akımı yaratabileceği gibi istenmeyen rüzgâr akımı meydan getirerek cisimlerde yapısal titreşimler ve gürültü gibi istenmeyen durumları da meydana getirebilmektedir. Bu çalı...

Bu çalışmada, bir akış alanı içerisine sıralı şekilde yerleştirilen iki silindir (kontrol silindiri ve ısıtılan silindir) arasındaki mesafenin alt akış bölgesindeki ısıtılan silindir etrafındaki ısı transferine etkisi deneysel olarak incelenmiştir. Isıtılan silindir alüminyumdan imal edilmiş olup, içerisine elektrikli rezistans yerleştirilerek sili...

Bu çalışmada 25 mm çaplı düz yüzeyli bir silindire saat yönü ve saatin tersi yönünde farklı dönme oranları (α=0.5, 1, 1.5, 2, 4) uygulandığında silindir etrafında oluşan akış yapısı deneysel olarak incelenmiştir. Öncelikle silindirin sabit olduğu durum için deneyler gerçekleştirilmiş, daha sonra da silindire farklı hızlarda ve yönlerde silindirin m...

The aim of the present study is to investigate the experimental performance of a solar dryer by using a novel type of a drying chamber for increasing the drying performance and ensuring homogeneous drying. The drying system (SDS) consisted of a new type of a drying chamber and a solar air collector, which were designed, made, and tested in Osmaniye...

This study investigated experimentally the flow regime with a face shield on a face mannequin placed at different distances (L=50 cm and L=150 cm to source of flow), i.e., perpendicular to the channel or at an angle of 10°, through the PIV (Particle Imaging Velocimetry) method along with the dye experiments, based on which the face shield and dye i...

Bu çalışmada, dairesel bir silindir etrafındaki ısı transferinin incelenebilmesi için tasarlanmış bir sıcaklık ölçüm sistemi ele alınmıştır. Çalışmada, alüminyum bir silindir içerisine yerleştirilen elektrikli rezistans vasıtasıyla silindir yüzeyinde sabit sıcaklık elde etmek için bir sıcaklık ölçüm sistemi tasarlanmış ve ilk ölçümlerin değerlendir...

The flow patterns of the wake region of a rotationally oscillating cylinder were investigated experimentally by using the Particle Image Velocimetry (PIV) technique and dye visualization. The experiments were conducted at Reynolds number Re = 1000 and different values of oscillation amplitude (θA = 60°, 120°, 180°) and frequency ratio (FR = 0.8, 1....

The aim of this study was to investigate the effects of installing the grooved and smooth control cylinder upstream of a circular bare cylinder with a focus on the heat transfer and the flow structure behind the bare cylinder. The Reynolds number based on the bare cylinder diameter (D = 50 mm) is Re = 5 000. Control cylinder has a constant diameter...

In this experimental study, flow structure over a three bladed vertical axis Darrieus turbine is investigated experimentally for Reynold Number, Re=9000 in an open channel. Rigidity ratio (σ), angle of attack, optimum values of blade chord length (CL), turbine radius (R) and height of turbine blades (H) are used as approximately 1.1 and α=-2°, CL=5...

Bu çalışmada farklı derece gün bölgelerinde yer alan iki farklı şehirdeki yeşil çatı uygulamasının ısıtma ihtiyacına, çevre emisyonlarına ve yakıt maliyetine etkisi iki farklı iç ortam sıcaklıklarında incelenmiştir. Binanın, ısı yalıtımsız, ısı yalıtımlı ve yeşil çatılı olma durumları için ısıtma ihtiyacı, aylık yakıt maliyeti ve emisyon değerleri...

In this study, the visualization of the flow structure around a circular cylinder was investigated with dye injection experiments. The experiments were carried out in the closed-circuit open water channel in Osmaniye Korkut Ata University. Experiments have been studied on a circular cylinder at different rotational speeds. Experiments were carried...

The office is an important part of our daily life, people spend most of their time doing works inside of the office and therefore the quality of the indoor environment is a significant factor affecting the productivity and happiness of office users. Many factors ınfluence the pattern of airflow: indoor air quality, thermal comfort and energy saving...

The purpose of this study is to investigate the rheological properties of sumac extract in different concentrations at different temperatures as well as its flow behavior in sudden expansion-contraction and at 90 o elbow with CFD. The rheological behaviour of sumac extract in different concentrations (45.65%, 50.44%, 55.53%, 60.32%, and 65.13% tota...

Nowadays, heat energy and the photovoltaic (PV) principle are widely used for generating electric power. PV panels can convert a limited portion of the solar radiation falling on them into electric power. Photovoltaic-thermal (PV-T) systems are used in order to remove and evaluate the heat load caused by the solar radiation. In this study, an exper...

The energy demand for heating in buildings in a residential area depends on the weather conditions of the area, the architectural characteristics and thermal-physical characteristics of the buildings, as well as the number of buildings in the settlement and the population of the settlement, accordingly. This study aimed to numerically determine the...

Bu çalışmada, içerisinde insan, buzdolabı, lamba ve bilgisayar bulunan ve boyutları 3x4x3,5 m olan bir ofise jet lüle ile üfleme yapılmıştır. Ofisin Osmaniye ilinde yaz şartlarında olduğu varsayılmış ve içerisine %100 taze hava verildiği düşünülerek ısı kaybı kazancı hesabı yapılmıştır. Bu hesaba göre debi ve üfleme sıcaklığı bulunmuştur. Duvarlara...

Food preservation with drying is an important food storage method that has been used by people since early ages. The main principle of the drying process is to remove the moisture contained in the food material. In this way, microbiological and enzymatic changes in the product will be prevented or limited. In this study, the drying characteristics...

One of the flow characteristics which affect the homogeneous mixture, the amount of power spent and the efficiency in the mixer tanks is the swirling flow at the tip of the impeller. Ensuring the mixing process to be more efficient is provided by preventing the stagnant part in the tank and preventing swirling. In this study, the effects of three d...

In thermal insulation applications, it is essential to determine the insulation thickness in accordance with the standards. The optimum thermal insulation thickness determined according to these conditions is called the optimum heat insulation thickness in the literature. Numerical calculation methods are used in our country to determine the optimu...

Seralar; çeşitli bitkilerin yetiştirilmesine uygun koşulların sağlanması amacı ile çevre şartları kontrol edilebilen veya belirlenen cam, plastik, fiberglas gibi ışığı geçiren malzemelerle örtülü yapı veya yapı elemanlarıdır. Başka bir deyişle sera; iklime bağlı kalmadan, tüm yıl boyunca ekonomik olarak bitkilerin yetiştirilebileceği yerlerdir. İyi...

The experimental study focuses on investigating the aerodynamic flow structure and the characteristics over non-slender diamond wing having low sweep angle (Λ = 51°). The vortical flow on the surface of the non-slender diamond models was investigated using dye-flow visualization and a stereoscopic particle image velocimetry (SPIV) technique. The ne...

In this study, the dehydration behavior of zucchini using solar assisted drying system was examined according to 22 thin layer drying models available in literature. The correlation coefficient (R2), chi-square (χ2) and root mean square error (RMSE) values were calculated to check the suitability of models by non-linear regression analysis. It was...

Excessive heating of electronic equipments may cause both decreasing thermal performance of system and undesirable consequences such as increased thermal stresses and mechanical defects in the system. In the literature, there are many studies including applications of thermal analysis and technologies in order to make cooling more effective. In thi...

Due to its light weight and high strength, carbon fiber reinforcement resin based composite (CFRC) has been widely used in aerospace, military, and many other industries. As the manufacturing technology develops, the geometry of CFRC components has seen significant changes, such as closed surface from the traditional open surface, or quite sophisti...

This paper reports the entropy generation of a two-dimensional, non-isothermal, steady, hydrodynamically and thermally fully-developed flow of an incompressible, non-Newtonian shear thinning fluid between two infinite parallel plates. The inelastic fluid is modeled by a two parameter Carreau constitutive equation with an exponential temperature dep...

To prevent the decrease in the efficiency of the electronic components of the devices which are frequently used in defense, automotive, medicine, space, energy, etc. fields with today’s developing technology, cooling of these components is of great importance. Heat transfer is a very important precaution for proper design and safe operation of elec...

The conditions must be provided for people to be comfortable in their work areas. The climate studies have an important role at this stage. Because of the low quality of the air in the environment, the activity causes little complaints such as breathing, headache, fatigue and loss of appetite. In order to change the ambient air and compensate for t...

Just as the new technologic developments are taking the place the earlier systems in every aspect of daily life, in air conditioning field also the new systems are replacing the conventional and obsolete ones. Current central air conditioning systems are improving and adapting in a parallel manner towards new developments and technologies. Variable...

Nowadays, the use of solar radiation is very important for some applications. Knowledge of global solar radiation distribution is needed for the design of solar energy systems for these applications. Many parameters affect the production of solar energy and conversion efficiencies and location conditions of PV panels. One of the most vital paramete...

This paper reports the entropy generation of a two-dimensional, non-isothermal, steady, hydrodynamically and thermally fully-developed flow of an incompressible, non-Newtonian shear thinning fluid between two infinite parallel plates. The inelastic fluid is modeled by a two parameter Carreau constitutive equation with an exponential temperature dep...

This study investigates the nanofluid for a nonisothermal channel flow under the effect of a constant pressure gradient acting along the channel axis. In the present study, the theoretical and experimental models commonly encountered in the literature (Einstein, Batchelor, Brinkman, Wang, Chen and Heyhat models) are compared by observing temperatur...

This paper investigates the prediction of solar radiation model and actual solar energy in Osmaniye, Turkey. Four models were used to estimate using the parameters of sunshine duration and average temperature. In order to obtain the statistical performance analysis of models, the coefficient of determination (R²), mean absolute percentage error (MA...

Solar energy production and economic evaluation are analyzed, in this study, by using daily solar radiation and average temperature data which are measured for 3 years in the Osmaniye province in Turkey. Besides, this study utilizes the photovoltaic-(PV-) based grid connected to a power plant which has an installed capacity of 1 MW investment in el...

Mixing Tanks are commonly used for blending a mixture which is occurred from two or more materials. The core mixing design topics are homogeneous blending in tanks, dispersion of gases in liquids, suspension and distribution of solids in liquids, liquid–liquid dispersions and heat transfer. Mixing processes are generally used in a wide range of ind...

Impinging flow jets provide an efficient way to transfer energy in many industrial applications. A directed liquid or gaseous flow against a heated surface can efficiently transfer large amounts of thermal energy between the surface and the fluid. Flow over squared blocks is common in many industrial applications for instance cooling of electronic...

Solar energy production and economic evaluation are analyzed, in this study, by using daily solar radiation and average temperature data which are measured for 3 years in the Osmaniye province in Turkey. Besides, this study utilizes the photovoltaic-(PV-) based grid connected to a power plant which has an installed capacity of 1 MW investment in el...

Disposal of waste tires is one of the most important problems that should be solved. This problem can be solved by considering waste tires for production of hydrogen or fuel for diesel engines. This paper presents the studies on the performance and emission characteristics of a four stroke, four cylinders, naturally aspirated, direct-injected diese...

This paper reports the entropy generation of a two-dimensional, non-isothermal, steady, hydrodynamically and thermally fully-developed flow of an incompressible, non-Newtonian shear thinning fluid between two infinite parallel plates. The inelastic fluid is modeled by a two parameter Carreau constitutive equation with an exponential temperature dep...

In this work, the flow behaviors of multiple circular cylinders in a staggered arrangement, located in a rectangular duct with a narrow gap are studied experimentally using laser particle image velocimetry (PIV). Each cylinder is positioned at the corner of an equilateral triangle with a pitch ratio of 2. d. It is known that multiple cylinders in s...

The aim of this numerical study is investigate the flow structure past a rectangular, triangular and semicircular cavity of length-to-depth ratio of 2:1. A commercial software FLUENT is used for numerical results. The influence of cavity shape on the flow structure and heat transfer of the cavity is the focal point of this paper. Cavities are heate...

Turkey is a dependent country on FOREIGN energy and the consuming of electric energy is getting increased very fast in terms of the development of industry and increment of the population. Although Turkey has a wide range of energy resources such as coal, natural gas, petroleum etc., they are limited. Because of this, renewable energy sources are g...

Nowadays, solar energy has taken a significant place in many industries and APPLICATION areas in terms of photovoltaic cell and supplying energy to natural processes like photosynthesis. As one of the most important renewable energies, solar energy has certain accessibility in many parts of the world such as building thermal systems and photovoltai...

In this paper, economical and environmental performance of thermally insulated and non-insulated for a sample building located in OSMANIYE. Turkey is presented. Thermal performance of building is determined according to TURKISH Standard 825 (TS 825) ‘‘Thermal Insulation Requirements for Buildings”. The yearly energy needs of the building (Q) rating...

The main goal of this study is to investigate the economic analysis of some efficiency enhancement projects such as thermal insulation, lightening and solar collector APPLICATION for a sample building. TURKISH Standard 825 (TS 825) ‘‘Thermal Insulation Requirements for Buildings” is used for determining of yearly energy needs of the building (Q). L...

Bu çalışmada sabit basınç gradyanının etkisi altındaki nanoakışkanın izotermal olmayan kanaldaki akışı sayısal olarak incelenmiştir. Çalışmada literatürde sıklıkla karşılaşılan deneysel modeller (Wang, Chen ve Heyhat modeli) sıcaklık ve hız profillerine bakılarak karşılaştırılmış ve birbirlerine olan uyumları incelenmiştir. Kanal içindeki alümina-...

The present experimental work investigates the near surface flow structure and aerodynamic characteristics of X-45 type non-slender delta wing planform using dye visualization, Stereoscopic Particle Image Velocimetry (stereo-PIV) and aerodynamic load measurements. The instantaneous images are acquired on the plan-view plane within 5 o ≤ α ≤ 20 o to...

Bu calismada sabit basinc gradyaninin etkisi altindaki nanoakiskanin izotermal olmayan kanaldaki akisi sayisal olarak incelenmistir. Kanal akisinin cozumunde akisin iki boyutlu, izotermal olmayan, sikistirilamaz, hidrodinamik ve isil olarak tam gelismis ve surekli oldugu kabul edilmistir. Kanal alt ve ust cidarlarina sabit isi akisi sinir sarti uyg...

The aim of this study is to investigate the natural convection heat transfer problem using numerical method within vertical wall disposed semi-cylindrical cavity (well). The calculations are made for semi-cylindrical with different forms disposed in the cavity for different Rayleigh numbers (Ra=103, Ra=104, Ra=105, Ra=106 ). Average Nusselt numbers...

The aim of this numerical study is to investigate flow properties of various concentration of Al2O3 Nano-dispersion mixed in water as base fluid at some common components of pipe system: elbow, sudden contraction and sudden enlargement. The volume concentrations of Al2O3 Nano fluid are taken as 2.0 %, 5.0%, and 8.0%. Results are compared with water...

Hydrogen energy alternative to fossil fuels is considered as an energy source of the future. There are different methods for production of hydrogen, but their most preferred is electrolysis method. Electrocatalytic electrodes for electrolysis process are investigated. It is asked that the electrodes must have low overpotential [1]. In this study, w...

The aerodynamics of unmanned combat air vehicles (UCAVs), which can be represented by simplified planforms, including delta wings, and micro air vehicles (MAVs) have taken important place in recent years. Vortex dynamics over delta wing and the effects on delta wing performance have become an important key role. The aim of this investigation is to...

Abstract: A turbulent boundary layer incident upon a perforated plate, which is bounded on one side by an enclosed cavity and on the other side by a free stream, can give rise to highly coherent oscillations. The purpose of this study is to attenuate these oscillations with proper surface elements. Two different surface elements are taken into cons...

This paper investigates the entropy generation of a nonisothermal, incompressible Newtonian fluid flowing under the effect of a constant pressure gradient in plane Poiseuille flow. The effects of variable viscosity and thermal conductivity are also included. The viscosity and thermal conductivity of the fluid exhibit linear temperature dependence a...

In this study, wind energy potential as a result of the distribution of wind speed is studied in urban area of Osmaniye where is on the east of the Mediterranean in Turkey. Weibull and Rayleigh distribution methods which mostly used for this type of wind energy studies are investigated. As a result of this, approximate wind potential energy is obta...

Today, hybrid system, to increase the use of renewable energy sources has become one of the most important applications. This system is composed of a combination of wind and sun was established and has been started up in Karacaoglan campus of the University of Osmaniye Korkut Ata. In this study, the system components are introduced and for the futu...

Experiments are carried out in order to investigate the flow structure past a rectangular, triangular and semi-circular cavity of length-to-depth ratio of 2:1 using the Particle Image Velocimetry (PIV) technique. The experiments are performed in a large scale water channel with three different upstream velocities resulting in Reynolds numbers of 12...

An experimental investigation of the flow over the rectangular body located in close proximity to a ground board was reported using the particle image velocimetry (PIV) technique. The present experiments were conducted in a closed-loop open surface water channel with the Reynolds number, Re H = 1.2×10 4 based on the model height. In addition to the...

An experimental investigation of the flow over the rectangular body located in close proximity to a ground board was reported using the particle image velocimetry (PIV) technique. The present experiments were conducted in a closed-loop open surface water channel with the Reynolds number, ReH= 1.2 × 104 based on the model height. In addition to the...

Genel anlamda karıştırıcı tanklar; iki veya daha fazla malzemeden meydana gelen bir bileşimi hazırlamak için gazlar, sıvılar veya katıların birbiri ile karıştırıldığı kapalı kaplardır. Karıştırma kapsamına giren alanlarda çok sayıda ve değişik tipte cihazlar kullanılmaktadır. Karıştırıcının mekanik dönüş hareketini sağlamak için elektrik enerjisine...

Flow through a sudden contraction occurs in a variety of engineering applications including injection moulding, extrusion, thermoforming and many polymer melt processing applications. Instabilities observed during polymer melts processing can have an important limiting factor affecting production rates in many industrial area. Analysis of contracti...

Flow through a sudden contraction occurs in a variety of engineering applications including injection moulding, extrusion, thermoforming and many polymer melt processing applications. Instabilities observed during polymer melts processing can have an important limiting factor affecting production rates in many industrial area. Analysis of contracti...

This Brief Communication investigates the effect of variable viscosity and thermal conductivity of a nonisothermal, incompressible Newtonian fluid flowing under the effect of a constant pressure gradient in plane Poiseuille flow. The viscosity and thermal conductivity of the fluid exhibit linear temperature dependence and the effect of viscous heat...

It is known that flow past a perforated plate can give rise to purely hydrodynamic, self-sustained oscillations, which have a wavelength of the order of the plate length. The present investigation demonstrates that these oscillations can be effectively attenuated by three-dimensional surface elements in the form of vortex generators. A technique of...

It is known that flow past a perforated plate can give rise to purely hydrodynamic, self-sustained oscillations, which have a wavelength of the order of the plate length. The present investigation demonstrates that these oscillations can be effectively attenuated by three-dimensional surface elements in the form of vortex generators. A technique of...

This Brief Communication investigates the effect of variable viscosity and thermal conductivity of a nonisothermal, incompressible Newtonian fluid flowing under the effect of a constant pressure gradient in plane Poiseuille flow. The viscosity and thermal conductivity of the fluid exhibit linear temperature dependence and the effect of viscous heat...

In this paper the linear stability of plane Poiseuille flow is studied for a non-Newtonian liquid having an exponential viscosity-temperature dependence. Non-Newtonian behavior of the fluid is modeled through Carreau rheological equation. Channel walls are kept at constant but different temperatures. Steady base flow equations and equations describ...