Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7148

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Author: search.filters.author.Erek, Aytunç

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Now showing 1 - 5 of 5
  • Article
    Citation - WoS: 18
    Citation - Scopus: 21
    Experimental and Numerical Investigation of Forced Convection in a Double Skin Façade
    (MDPI Multidisciplinary Digital Publishing Institute, 2017) İnan, Tuğba; Başaran, Tahsin; Erek, Aytunç
    Flow and heat transfer of the air cavity between two glass façades designed in the box window type of double skin façade (DSF) was evaluated in a test room which was set up for measurements in the laboratory environment and analyzed under different working conditions by using a computational fluid dynamics tool. Using data from the experimental studies, the verification of the numerical studies was conducted and the air flow and heat transfer in the cavity between the two glass façades were examined numerically in detail. The depth to height of the cavity, the aspect ratio, was changed between 0.10 and 0.16, and was studied for three different flow velocities. Reynolds and average Nusselt numbers ranging from 28,000 to 56,500 and 134 to 272, respectively, were calculated and a non-dimensional correlation between Reynolds and Nusselt numbers was constructed to evaluate the heat transfer from the cavity (except inlet and outlet sections) air to the inside environment and it could be used the box window type of DSF applications having relatively short cavities.
  • Article
    Citation - WoS: 12
    Citation - Scopus: 16
    Numerical Optimization of a Fin-Tube Gas To Liquid Heat Exchanger
    (Elsevier Ltd., 2012) Bilir, Levent; İlken, Zafer; Erek, Aytunç
    The influence of plate fin, fin tube and protrusion parameters on heat transfer and pressure drop characteristics of a finned tube gas to liquid heat exchanger is examined in this study. The optimization of plate fin, fin tube and protrusion dimensions as well as protrusion locations on plate fin surface is performed numerically using a computational fluid dynamics (CFD) program named "Fluent". The dimensions of the plate fin of a commercially available combi boiler apparatus heat exchanger are taken as basic dimensions. As the first step, the best plate fin and fin tube geometry is determined. Secondly, the best dimensions for three different protrusions (balcony, winglet and imprint) and their most suitable locations on the plate fin surface are found. Finally, the cumulative effects of several combinations of these three protrusions on the plate fin surface are analyzed. The placement combinations of protrusions are decided according to the results obtained for the individual effect of each protrusion. The fin named as I5B2W3 is found to be the most efficient fin among the investigated cases. A comparison with a numerical and computational study is also performed to validate the numerical results of the present study. © 2011 Elsevier Masson SAS. All rights reserved.
  • Article
    Citation - WoS: 15
    Citation - Scopus: 17
    Heat Transfer and Pressure Drop Characteristics of Fin-Tube Heat Exchangers With Different Types of Vortex Generator Configurations
    (Begell House Inc., 2010) Bilir, Levent; Özerdem, Barış; Erek, Aytunç; İlken, Zafer
    A fin-and-tube heat exchanger with three different types of vortex generators is investigated in this study in order to observe the effects of these vortex generators on heat transfer and pressure drop characteristics. The individual as well as the cumulative influences of the vortex generators on the performance of a heat exchanger are examined. The numerical analyses are performed using a computational fluid dynamics (CFD) program named "Fluent". Firstly, each vortex generator type is placed at four different locations on the fin to determine its best location in terms of heat transfer and pressure drop values. After the determination of the best location on the fin for a vortex generator of each type, two different models with all three types of vortex generators are created and analyzed numerically. The investigation of the cumulative effect of three different vortex generators is the novelty of the study. The results of the study show that the use of three different vortex generators together increases heat transfer rate with a moderate increase in pressure drop value. The comparison of the present study results with an experimental and numerical study showed also a good agreement. © 2010 by Begell House, Inc.
  • Article
    Citation - WoS: 152
    Citation - Scopus: 172
    Experimental and Numerical Investigation of Thermal Energy Storage With a Finned Tube
    (John Wiley and Sons Inc., 2005) Erek, Aytunç; İlken, Zafer; Acar, Mehmet Ali
    A latent heat thermal energy storage system using a phase change material (PCM) is an efficient way of storing or releasing a large amount of heat during melting or solidification. It has been determined that the shell-and-tube type heat exchanger is the most promising device as a latent heat system that requires high efficiency for a minimum volume. In this type of heat exchanger, the PCM fills the annular shell space around the finned tube while the heat transfer fluid flows within the tube. One of the methods used for increasing the rate of energy sto rage is to increase the heat transfer surface area by employing finned surfaces. In this study, energy storage by phase change around a radially finned tube is investigated numerically and experimentally. The solution of the system consists of the solving governing equations for the heat transfer fluid (HTF), pipe wall and phase change material. Numerical simulations are performed to investigate the effect of several fin parameters (fin spacing and fin diameter) and flow parameter (Re number and inlet temperature of HTF) and compare with experimental results. The effect of each variable on energy storage and amount of solidification are presented graphically.
  • Article
    Citation - WoS: 101
    Citation - Scopus: 132
    Effect of Geometrical Parameters on Heat Transfer and Pressure Drop Characteristics of Plate Fin and Tube Heat Exchangers
    (Elsevier Ltd., 2005) Erek, Aytunç; Özerdem, Barış; Bilir, Levent; İlken, Zafer
    In this study, the influences of the changes in fin geometry on heat transfer and pressure drop of a plate fin and tube heat exchanger are investigated, numerically. A computational fluid dynamics (CFD) program called Fluent is used in the analysis. The segment of one tenth of fin is used in the modeling, due to symmetrical condition. The results of heat transfer, static, and total pressure drop values of ten different fins are tabulated and the normalized values of them are, also, given for the comparison of the models. The distance between fins is found to have a considerable effect on pressure drop. It is observed that placing the fin tube at downstream region affects heat transfer positively. Another important result of the study is that increasing ellipticity of the fin tube increases the heat transfer while it, also, results in an important reduction in pressure drop.