İmalat Mühendisliği Bölümü Bildiri / Sunu / Poster Koleksiyonu
Bu koleksiyon için kalıcı URI
Güncel Gönderiler
Öğe ELMAS-SU NANOAKIŞKANI KULLANILAN FARKLI KANATÇIK UZUNLUKLU VE AÇILI BİRLEŞİK JET AKIŞLI KANALLARDA ISI TRANSFERİNDEKİ İYİLEŞMENİN ANALİZ EDİLMESİ(15.01.2023) Alnak, Dogan EnginEspecially in the energy-intensive industrial sector; attention is paid to ensure that all kinds of devices and equipment produced are systems with high energy efficiency and long life. The most important obstacle in front of this situation is the heating problem in technologically advanced devices. The combined application of the cross flow-impinging jet flow combined jet flow heat transfer method can create a high-capacity cooling method. In this study, heat transfer from the cube and hollow models was numerically investigated using water and Diamond-Water nanofluid in combined jet flow channels with 30o and 90o angled fins. The fins were located at a fixed N=1.5D distance from the impinging jet inlet to the channel; fin lengths were taken as K=D and K=2D. Numerical analysis was carried out by solving energy and Navier-Stokes equations with the k- turbulence model using the Ansys-Fluent program in three-dimensional and steady. While the upper and lower surfaces of the fin and channel are adiabatic; a constant heat flux of 1000 W/m2 was applied to the model surfaces. The Reynolds number range studied for fluids is 7000-11000. Thermophysical properties of Diamond-Water nanofluid with 2% volumetric concentration were obtained with the help of equations found in the literature. The results of the study were compared with the correlation obtained as a result of the experimental study in the literature and the results were found to be compatible. The results were analyzed as variations in the mean Nu number depending on the fin length for each cube and hollow model surface in the channels. In addition, velocity-streamline and temperature contour distributions of the Diamond-Water nanofluid were visualized for different fin angles (30o and 90o) and lengths (K=D and K=2D) at Re=11000. The mean Nu number (Nuort) and model surface temperature values (Tort) were evaluated comparatively in cases where K=D and K=2D at different Reynolds numbers and water and Diamond-Water nanofluids are used for all model surfaces in the channels. As a result, 80.35% and 90.03% increases in Nuort values were obtained for cube and hollow model surfaces, respectively, in the 90o angled and K=2D length finned channel using Diamond-Water nanofluid at Re=11000 compared to the channel without fin and using water fluid.Öğe COOLING OF HEATED SURFACES IN COMBINED JET FLOW CHANNELS WITH DIFFERENT FIN POSITIONS AND SiO2-WATER NANOFLUID(15.01.2023) Alnak, Dogan EnginThe increase in energy prices around the world negatively affects production costs, especially in the heat-intensive industry. However, the increase in the amount of heat production per unit volume in electronic devices whose dimensions have decreased with the development of technology is an undesirable situation for the progress process in this sector. The co-application of cross-flow-impinging jet flow as a combined jet flow increases the cooling capacity of high-temperature surfaces. In this study, heat transfer from trapezoidal and hollow model surfaces and flow structures in channels were investigated numerically using water and SiO2-Water nanofluids in H=4D height channels with combined jet flow with 30o and 60o angled fins. The fins were located at N=D and N=2D positions from the impinging jet inlet. The fin length (K) is 2D. Numerical analysis was carried out by solving energy and Navier-Stokes equations with the k- turbulence model using the Ansys-Fluent program in three-dimensional and steady. While the upper and lower surfaces of the fin and channel are adiabatic; model surfaces have a constant heat flux of 1000 W/m2. The Reynolds number range studied for fluids is 7000-11000. Thermophysical properties of SiO2-Water nanofluid with 2% volumetric concentration were obtained with the help of equations found in the literature. The results of the study were compared with the correlation obtained as a result of the experimental study in the literature and the results were found to be compatible. The results were evaluated as the variation of the mean Nu number for each trapezoidal and hollow model surface in the channels. However, velocity-streamline and temperature contour distributions of SiO2-Water nanofluid were visualized for different fin angles (30o and 60o) and placements (N=D and N=2D) at Re=11000. Nuort and Tort values were analyzed comparatively when water and SiO2-Water nanofluid were used for all model surfaces in the channels at different values of Reynolds number and N=D and N=2D fin positions. As a result, 46.65% and 51.27% increases in Nuort value for trapezoidal and hollow model surfaces, respectively, were obtained compared to water fluid when N=2D fin position and SiO2-Water nanofluid were used for Re=11000.Öğe EVALUATION OF HEAT TRANSFER INCREASE ACCORDING TO THE DISTANCE OF THE FIN FROM THE IMPINGING JET INLET IN COMBINED JET FLOW CHANNELS USING TIO2-WATER NANOFLUID(07.01.2023) Alnak, Dogan EnginToday, when the transition of world countries to green energy is discussed, the method of obtaining energy and reducing the amount of use in all kinds of sectors are among the most important and crucial issues. The increase in the cost of energy affects the production costs, especially in the heat-intensive industry. However, the increase in the amount of heat production per unit volume in electronic devices whose dimensions have decreased with the development of technology; this is undesirable for the progress process in the sector. The cross-flow cooling method, which is used to increase heat transfer from electronic elements, is one of the most widely used methods. This method is based on the principle of sending the cold fluid over all the components with a fan, thereby cooling the entire electronic components. Another method of heat transfer is impinging jet cooling where cold fluid is locally sprayed onto an element with a high temperature with a nozzle. For this reason, it is difficult to reach the conditions that can keep the whole circuit safely with a single type of cooling method. Implementing the impinging jet and cross flow cooling method together can create a beneficial situation with high cooling capacity. When the literature is evaluated, it is seen that the number of combined jet flow studies in which impinging jet and cross flow are applied together using TiO2-Water nanofluid, which exhibits high heat transfer performance, is quite low. In this study, heat transfer and flow structures in channels, which are cube and cavity models, were numerically investigated using water and TiO2-Water nanofluids in H=3D height channels with combined jet flow with 30o and 60o angled fins. The fins are located at N=D and N=2D positions from the impinging jet inlet. Numerical analysis was carried out by solving the energy and Navier-Stokes equations with the k- using the Ansys-Fluent program in a three-dimensional and steady. While the upper and lower surfaces of the fin and channel are adiabatic; a constant heat flux of 1000 W/m2 was applied to the model surfaces. The Reynolds number range studied for fluids is 5000-9000. Thermophysical properties of 2% volumetric concentration TiO2-Water nanofluid were obtained with the help of equations found in the literature. The results of the study were compared with the correlation obtained as a result of the experimental study in the literature and the results were found to be compatible. The results were analyzed as changes in the mean Nu number for each cube and cavity model surface in the channels.Öğe Investigation of the Effect of Length Change of Fin Placed in Cross Flow-Impinging Jet Flow Channels with Al2O3 -Water Nanofluid on Flow Structure and Heat Transfer(07.01.2023) Alnak, Dogan EnginWith the impact of global climate change being felt in recent years, efforts to transition to a green economy have started to gain momentum all over the world, especially in European countries. In this context, it is aimed to evaluate the production of energy in terms of sustainability; and to make its use economical and efficient. For this, first of all, especially in the energy-intensive industrial sector; Attention is paid to ensure that all kinds of devices and equipment produced are systems with high energy efficiency and long life. With the technological progress in the electronics industry sector in recent years; decrement in size and volume. However, although high-tech products in small volumes are advantageous for users; This creates a troublesome situation for producers, which means more heat is produced in unit volume. This situation necessitates the use of more effective cooling techniques in electronic devices. The cross-flow cooling method, which is used to increase heat transfer from electronic elements, is one of the most widely used methods. This method is based on the principle of sending the cold fluid over all the components with a fan, thereby cooling the entire electronic components. Another method of heat transfer is impinging jet cooling where cold fluid is locally sprayed onto an element with a high temperature with a nozzle. For this reason, it is difficult to reach the conditions that can keep the whole circuit safely with a single type of cooling method. Implementing the impinging jet and cross flow cooling method together can create a beneficial situation with high cooling capacity. Although Al2O3-Water nanofluid is a heat transfer fluid used extensively in heat transfer research; In the literature research reached, it has been determined that the number of jet flow studies in which cross flow and impinging jet flow are applied together is quite low.Öğe EXAMINATION OF THE VARIATION OF THERMAL PERFORMANCE WITH JET-PLATE DIST ANCE iN IMPINGING JET-CROSS FLOW CHANNELS HAVING FiN AND USED GRAPHENE OXIDE-WATER NANOFLUID(18.06.2022) Alnak, Dogan EnginWith the developing technology, high performance and small voluıne electronic components can be produced; the temperatures of these elements exceed the limit values that can be considered safe. Current conventional heat transfer methods fall short of cooling these hightech products. The heat transfer from electronic devices can be increased considerably with the impinging jet-cross flow. In this study, heat transfer from the crown and cavity pattemed surfaces was numerically analyzed by using water and 0.02% volumetric concentration GO (Graphene Oxide)-Water nanofluid in channels having differentjet-plate distances (H=3D and 4D) and fınless and fınned with impinging jet-cross flow. Numerical analysis was carried out steady and in three dimensions by using the Ansys-Fluent program with k-c turbulence model; the thermophysical properties of GO-Water nanofluid were obtained experimentally. Three models were positioned on the channels, taking into account the channel dimensions in the studies in the literature. When the fın angle is fıxed 90°; the distance of the fın in the channel from the impinging jet inlet is N=2D. A constant heat flux of 1000 W/m2 was applied to the model surfaces in the channels. The Re number range of both cross flow and impinging jet flow is 7000-11000. In order to prove the accuracy of the study, the results were compared with the results in the Nu number equation obtained by the experimental study in the literature and it was seen that they were quite compatible. The results of the study were investigated as the variations of the mean Nu number at different jet-plate distances and in the fınless-fınned state for each pattemed pattem surface and pattem row. In addition, velocity and temperature contour distributions for GO-Water nanofluid were evaluated in impinging jet-cross flow channels with both model surfaces for Re=l 1000 and in fın positions with H=3D and 4D jetplate distances. However, the Performance Evaluation Nuınber (PEC) changes were determined for both model surface channels at different Re nuınbers and the pressure drop was interpreted against the Nu nuınber. In addition, the average Nu nuınber (Num) and surface temperature values (T m) for all three models in the channels were investigated. In the case of using nanofluids for all three crown and cavity model surfaces in H=3D and Re=ll000, the Num nuınbers are 64.78% and 56.56% higher than the fınless and water fluid, respectively; for H=4D, these values are 35.88% and 28.08% higher.Öğe INVESTIGATION OF HEAT TRANSFER IN COMBINED JET FLOW CHANNELS WITH DIFFERENT FIN ANGLES AND USING DIAMOND-WATER NANOFLUID(01.06.2022) Alnak, Dogan EnginWith traditional heat transfer methods, more energy is consumed and sufficient and desired heat transfer performance cannot be achieved. However, with the development of technology, the heating problem arises in high-performance and small-volume electronic components. In addition to the impinging jet, the heat transfer from the components of the electronic devices is considerably improved with the combined jet effect created by the cross flow. In this study, heat transfer and performance analysis (PEC) dependent pressure drop from trapezoidal and crown patterned surfaces were numerically investigatedÖğe INVESTIGATION OF THE EFFECT OF FiN ANGLE AT COOLING OF HOT PLATES OF IMPINGING JET-CROSS FLOW WITH GRAPHENE OXIDE-WATER NANOFLUID(18.06.2022) Alnak, Dogan EnginThe service life of modern, high-power, compact electronic components is affected by their heat dissipation capacity. It has become very important to cool the microchips, which are used in every stage of daily life and have been miniaturized with the developing technology, and the heating problem has arisen. In this study, the cooling of circular hollow and trapezoidal models with fixed 1000 W/m2 heat flux in the channels by impinging jet-cross flow using water and GO (Graphene Oxide)-Water nanofluid with 0.02% volumetric nanoparticle concentration was numerically investigated. The numerical study was carried out steady and in three dimensions by using the Ansys-Fluent program with k-E turbulence model. The thermophysical properties of the nanofluid were obtained experimentally. Considering the studies in the literature, three patterned models were placed in the channels in accordance with the channel dimensions. While the angles of the fins positioned in the channels are 30°and 60°; their distance from the impinging jet inlet is N=D. The channel heights are 4D and the Re number range ofthe fluids is 9000-13000. The accuracy and acceptability ofthe results obtained from the study has been proven by using the equation obtained as a result of experimental research. The results of the study were comparatively surveyed for water and nanofluid in the finless and finned conditions as changes in the average Nu number for each pattern in the channels. In addition, velocity and temperature contour distributions of the impinging jet-cross flow nanofluid flow were presented for different fin angles, taking into account the jet-pattern interactions. However, performance evaluation numbers (PEC) and average Nu number (Num) and surface temperature values (Tın) were evaluated for Re=13000 at different Reynolds numbers for all three models in the channels. At Re=13000, 16% and 17.57% increases in Num value were obtained for circular hollow and trapezoidal model surfaces in the impinging jet-cross flow channel with GO-Water nanofluid and 60° fin angle compared to the water flow and the finless channel, respectively. However, it was found that the PEC number values for the water fluid in both model surface channels were higher than the GO-Water nanofluid.Öğe INVESTIGATION OF THE COMBINED JET FLOW EFFECT ON FLOW AND HEAT TRANSFER APPLICATION IN THE CHANNEL(19.03.2022) Alnak, Dogan EnginWhile advancement of technology makes the lives of consumers easier, it causes manufacturers to encounter some problems in order to develop longer-lasting and energy-efficient devices. The biggest problem in this matter is overheating in electronic devices, which have a very high capacity compared to previous technologies. This motivates engineers working on heat transfer to turn to new advancement techniques in the field of electronic cooling and its applications. The method of increasing the heat transfer from the heated elements by the impact jet - cross flow combined jet effect, which has been applied recently, is used as an effective cooling technique. In this work, heat transfer from copper plate cube and trapezoidal surfaces in channels where impinging jet - cross flow combined jet flow was applied and the flow structures in the channels were numerically investigated by comparing them with each other. Numerical analysis was performed by solving the energy and Navier-Stokes equations as steady and three dimensional employing the k-ε turbulence model and Ansys-Fluent computer program. While the channel heights (H) for both channels are 3D and 6D, the fluid Re number range is 7000 - 11000. So as to direct the combined jet flow to the patterned surfaces in the channels, fins with a length equal to the D jet inlet diameter and an angle of 45o and 90o (θ) with the horizontal on the upper surface of the channels were placed. Water is used as a fluid in the channel, and the upper and lower surfaces of the channel and the fin are adiabatic. A constant heat flux of 1000 W/m2 was implemented to the designed surfaces. The results obtained from the study were matched with the experimental results of the study in the literature and it was found that they were compatible with one another. The results were analyzed as mean Nu number and surface temperature variations for each cube and trapezoidal surface according to their order in the channel. In Re = 11000 and H = 3D, contour distributions of velocity and temperature of impinging jet - cross flow combined jet flow along channels with cube and trapezoidal surfaces at without fin, 45o and 90o fin angles were presented. For Re = 9000 in H = 3D, it was found that the Num values of the cube and trapezoidal surfaces were 33.15% and 24.57% higher in the 90o fin angled channel than in the case of the without fin, respectively.Öğe A STUDY ON INCREASE COOLING CAPACITY OF MICROCHIPS WITH COMBINED JET FLOW(19.03.2022) Alnak, Dogan EnginElektronikteki en son gelişmeler, çoğunlukla minyatürleştirme ve modern elektronik cihazların entegrasyonu için geliştirilmiş verimlilik, güvenilirlik ve uzun süreli etkili soğutma işlemlerini içermektedir. Bununla birlikte, var olan en son ısıl yönetim teknikleri bile modern elektronik aletlerden olan soğutma taleplerini karşılamak için yeterli olmamaktadır. Fakat, çarpan jet- çapraz akış birleşik jet akış etkisi elektronik elemanların en küçük bileşeni olan mikroçiplerin soğutulmasını iyileştirici bir etkiye sahiptir. Bu çalışmada, yamuk ve oyuk desenli bakır plakalı yüzeylerin soğutulması çarpan jet - çapraz akış birleşik jet etkisi kullanılarak kanatçıksız ve 90o kanatçıklı farklı kanatçık konumlarına (N) ve kanal yüksekliklerine (H) göre birbirleriyle kıyaslamalı ve sayısal olarak incelenmiştir. Sayısal araştırmada sürekli ve üç boyutlu enerji ve Navier-Stokes denklemleri k-ε türbülans modelli Ansys-Fluent programından faydalanılarak çözülmüştür. Her iki desenli yüzeye sahip kanalda, kanatçık çarpan jet akış girişinden itibaren çapraz akışlı kanal girişine doğru N = D ve 1.5D olarak farklı konumlarda yerleştirilmiştir. Akışkan olarak kanalda su kullanılmış olup, kanatçık ve kanalın alt ve üst yüzeyleri adyabatiktir. Desenli yüzeyler, 1000 W/m2 sabit ısı akısına sahiptir. Jet-plaka arası mesafeler (H) 4D ve 6D olup, akışkan Re sayısı aralığı 5000-9000’ dir. Çalışmadan elde edilen sonuçlar, literatürdeki çalışmanın deneysel sonuçlarıyla kıyaslanmış ve birbirleriyle uyumlu oldukları saptanmıştır. Sonuçlar, her bir yamuk ve oyuk desenli yüzey için ortalama Nu sayısı ve yüzey sıcaklıklarının değişimleri olarak araştırılmıştır. Re = 9000 ve H = 6D’ de kanatçıksız ve 90o kanatçık açısında farklı kanatçık mesafelerinde yamuk ve oyuk desen yüzeyli kanallar boyunca çarpan jet-çapraz akış birleşik jet akışının hız ve sıcaklık konturu dağılımları sunulmuştur. Re = 7000’ de H = 4D kanal yüksekliği mesafesinde ve N = 1.5D kanatçık konumunda sırasıyla yamuk ve oyuk desenli yüzeyler için Num değerlerinin kanatçıksız durumdan %15.39 ve %16.31 daha fazla olduğu belirlenmiştir.Öğe HEAT TRANSFER IMPROVEMENT IN MICROCHIP ELECTRONIC CIRCUIT ELEMENTS BY COMBINED JET EFFECT(18.02.2022) Alnak, Dogan EnginElektronik devre üzerinde ne kadar çok mikroçip bulunabilirse o cihaz teknolojik olarak o denli gelişmiş olur. Fakat, küçük hacimlerde bulunan mikroçiplerin gelişimine engel olan aşırı ısınmaları sonucu sıcaklıklarının artışı önlenmelidir.Yüksek performanslı bir soğutma tekniği olan çarpan jet- çapraz akış mikroçiplerden olan ısı transferini iyileştirme potansiyeline sahiptir. Bu çalışmada, küp ve oyuk şekle sahip desenli bakır plakalı yüzeylerden olan ısı transferi çarpan jet - çapraz akış birleşik jet etkisi kullanılarak farklı kanatçık yerleşimlerine göre birbirleriyle karşılaştırmalı ve sayısal olarak incelenmiştir. Sayısal inceleme, sürekli ve üç boyutlu enerji ve Navier-Stokes denklemlerinin k-ε türbülans modeli ile Ansys-Fluent programının kullanılarak çözülmesiyle gerçekleştirilmiştir. Çapraz akışındesenli yüzeylere yönlendirilmesinde 60o sabit kanatçık açısına sahip kanatçık kullanılmış olup, kanatçığın uzunluğu D jet giriş çapına eşittir. Her iki desen şekilli kanalda, kanatçık jet akış girişinden itibaren çapraz akışlı kanal girişine doğru D ve 2D olarak farklı mesafelerde yerleştirilmiştir. Kanalda kullanılan akışkan su olup, kanalın alt ve üst yüzeyleri ve kanatçık adyabatiktir. Desenli yüzeyler, 1000 W/m2 sabit ısı akısına sahiptir. Jet-plaka arası mesafeler (H) 3D ve 6D olup, akışkan Re sayısı aralığı 11000-15000’ dir. Çalışmanın sonuçları, literatürdeki çalışmanın deneysel sonuçlarıyla kıyaslanmış ve birbirleriyle uyumlu oldukları belirlenmiştir. Sonuçlar, her bir küp ve oyuk desenli yüzeyler için ortalama Nu sayısı ve yüzey sıcaklık değişimleri olarak incelenmiştir. Re = 15000’ de kanatçıksız ve 60o kanatçık açısında ve farklı kanatçık mesafelerinde küp ve oyuk desenli kanallar boyunca birleşik jet akışın hız ve sıcaklık konturu dağılımları sunulmuştur. Re = 13000’ de H = 3D mesafede N = 2D için küp ve oyuk desenli kanatçıklı kanallarda kanatçıksız duruma göre kanallardaki tüm desenli yüzeyler için ortalama Nu sayısında (Num) sırasıyla %23.43 ve %22.58’ lik artışlar elde edilmiştir.Öğe COOLING OF CIRCUIT ELEMENTS WHOSE TEMPERATURES INCREASED DEPENDING ON THE FIN POSITIONS IN AN IMPINGING JET-CROSS FLOW CHANNEL(2021) Alnak, Dogan EnginGelişen teknoloji sayesinde devre elemanlarının boyutlarının küçülmesi ve artan işlemci kapasite ve hızları, elektronik elemanların sıcaklıklarının artmasına sebep olmaktadır. Cihazın sürdürülebilir bir şekilde çalışmasının sağlanabilmesi için devre elemanlarının soğutma kapasitelerinin artırılması gerekmektedir. Çarpan jet-çapraz akış soğutma tekniği ile devre elemanlarının sürekli ve verimli çalışması sağlanabilmektedir. Bu çalışmada, sabit ısı akılı bakır plakalı oyuk şekilli desenli yüzeylerin çarpan jet-çapraz akış tekniği ile farklı kanatçık konumlarına göre soğutulması sayısal olarak araştırılmıştır. Sayısal araştırma, sürekli ve üç boyutlu olarak enerji ve Navier-Stokes denklemlerinin k-ε türbülans modeli ile Ansys-Fluent programının kullanılarak çözülmesiyle gerçekleştirilmiştir. Kanaldaki akışı sıcaklığı artmış desenli yüzeylere yönlendirmede kullanılan kanatçığın açısı sabit 90o olup, uzunluğu D jet giriş çapına eşittir. Kanatçık, jet akış girişinden itibaren çapraz akışlı kanal girişine doğru D, 1.5 D ve 2D olarak farklı mesafelerde konumlandırılmıştır. Kanalda kullanılan jet akışkanı su olup, kanalın alt ve üst yüzeyleri ve kanatçık adyabatiktir. Oyuk şekilli desenli yüzeyler, 1000 W/m2’ lik sabit ısı akısına sahiptir. Jet-plaka arası mesafe 3D olup, jet Reynolds sayısı aralığı 5000-9000’ dir. Çalışmanın sonuçları, literatürdeki çalışmanın deneysel sonuçlarıyla karşılaştırılmış ve birbirleriyle tutarlı oldukları belirlenmiştir. Sonuçlar, her bir oyuk desenli yüzey için ortalama Nu sayısı ve yüzey sıcaklık değişimi olarak sunulmuştur. Re = 9000’ de kanatçıksız ve D, 1.5 D ve 2D kanatçık mesafeli kanallar için kanal boyunca çarpan jet-çapraz akışın hız ve sıcaklık konturu dağılımları karşılaştırmalı olarak değerlendirilmiştir. Re = 9000 için 2D mesafeli kanatçıklı kanalda ortalama Nu sayısı değerinin kanatçıksız ve D kanatçık mesafeli kanala göre sırasıyla %49.2 ve %17.13 daha fazla olduğu bulunmuştur.Öğe RESEARCH OF THE EFFECT OF FIN DESIGN ON THE COOLING OF HEATED ELECTRONIC COMPONENTS IN A CHANNEL WITH IMPINGING JET-CROSS FLOW(3.11.2021) Alnak, Dogan EnginElektronik bileşenler düşük voltaj akımda çalışırlar. Aşırı ısı, donanımların elektrik direncini düşürerek akımı artırır. Bunun sonucu olarak da cihazın performansında düşüş gözlenir. Bu durumu önlemek için elektronik elemanın ideal çalışma sıcaklığında olması gerekir. Çarpan jet-çapraz akış uygulamasıyla ısı transferi iyileştirilerek soğutma miktarı artırılmakta ve istenen verimli bir soğutma sağlanabilmektedir. Sunulan çalışmada, kanalda bulunan sabit ısı akısına sahip bakır plakalı oyuk desenli yüzeylerden olan ısı transferi çarpan jet-çapraz akış kullanılarak sayısal olarak araştırılmıştır. Sayısal inceleme, sürekli ve üç boyutlu olarak enerji ve Navier-Stokes denklemlerinin k-ε türbülans modelli Ansys-Fluent bilgisayar programının kullanılarak çözülmesiyle gerçekleştirilmiştir. Kanaldaki akışı ısınmış desenli yüzeylere yönlendirebilmek amacıyla 45o, 60o ve 90o açılı ve D jet giriş çapı uzunluğunda kanatçık, çarpan jet yüzeyiyle yatay olarak kanala yerleştirilmiştir. Kanalda kullanılan akışkan su olup, kanalın alt ve üst yüzeyleri ve kanatçık adyabatiktir. Oyuk desenli yüzeyler, sabit 1000 W/m2 ısı akısına sahiptir. Jet-plaka arası uzaklık 60 mm olup, jet Reynolds sayısı aralığı 7000-11000’ dir. Çalışmanın sonuçları, literatürdeki çalışmanın deneysel sonuçlarıyla karşılaştırılmış ve birbirleriyle tutarlı oldukları belirlenmiştir. Sonuçlar, her bir oyuk desenli yüzey için ortalama Nu sayısı ve yüzey sıcaklık değişimleri olarak sunulmuştur. Re = 9000’ de 45o, 60o ve 90o kanatçık açılı ve kanatçıksızÖğe INVESTIGATION OF THE VARIATION OF COOLING PERFORMANCE WITH THE CHANNEL HEIGHT IN A CHANNEL HAVING IMPINGING JET-CROSS FLOW(24.11.2021) Alnak, Dogan EnginThe cooling process by applying cross flow alone, which is one of the frequently used methods, may be insufficient for electronic circuit elements that reach high temperatures. Cooling with impinging jet, which is another cooling application, provides efficiency in cooling the regions locally. The combined use of impinging jet and cross flow improves cooling performance. In this study, the cooling of copper plate trapezoid surfaces with constant heat flux in the channel having two open sides was numerically investigated using a combination of impinging jet and cross flow. Numerical research was carried out by solving the energy and Navier-Stokes equations as three dimensional and steady, using the Ansys-Fluent program with k-ε turbulence model. With the aim of increase the cooling effect by directing the flow in the channel to the heated surfaces, a fin of 60o angle and D-jet inlet diameter length was placed in the channel horizontally with the impinging jet surface. The distances between the jet flow and trapezoid plate surfaces in the channel were taken as 45 mm, 60 mm and 90 mm. The jet fluid used in the channel is water and the jet Reynolds number range is 11000-15000. The upper and lower surfaces of the channel and the fin are adiabatic, and a constant heat flux of 1000 W/m2 was applied to the trapezoid patterned surfaces. The results of the study were compared with the experimental results of the study in the literature and they were found to be consistent with each other. The reached results were exhibited as the mean Nu number and surface temperature variation for each trapezoid surface. The contour distributions of velocity and temperature of the impinging jet-cross flow along channels were also evaluated. For Re = 15000, it was found that the mean Nu number value in the channel with 45 mm jet-plate distance and the fin was 57.80% higher than that of the 90 mm.
