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.Özerdem, BarışSubject: search.filters.subject.Heat transfer

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Now showing 1 - 4 of 4
  • 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: 14
    Citation - Scopus: 19
    A Numerical Simulation Study for the Human Passive Thermal System
    (Elsevier Ltd., 2008) Yıldırım, Eda Didem; Özerdem, Barış
    The objective of this study is to create a dynamic model representing a transient three-dimensional passive thermal model of the human body. The model is a multi-segmental, multi-layered representation of the human body with spatial subdivisions which simulates the heat transfer phenomena within the body and at its surface. In order to represent the mechanisms of heat transfer within the body, energy balance equations including conduction with adjacent tissue, heat storage, metabolic heat generation, and convective heat transfer due to the blood flow in the capillaries are taken into consideration for each tissue. The present model of the passive system accounts for the geometric and anatomic characteristics of the human body and considers the thermo-physical and the basal physiological properties of tissue materials. It is assumed that the body is exposed to combination of the convection, evaporation and radiation which are taken into account as boundary conditions when solving the passive thermal system equation. The model is capable of predicting human body temperature in any given environmental conditions. Finite difference solution scheme is used to find out the temperature distribution of human body. The results are compared with the experimental data of previous studies present in the literature. Consequently, the numerical results of present model show good agreement with the experimental data.
  • 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.
  • Article
    Citation - WoS: 58
    Citation - Scopus: 73
    Measurement of Convective Heat Transfer Coefficient for a Horizontal Cylinder Rotating in Quiescent Air
    (Elsevier Ltd., 2000) Özerdem, Barış
    The present paper deals with convective heat transfer from a horizontal cylinder rotating in quiescent air, experimentally. The average convective heat transfer coefficients have been measured by using radiation pyrometer, which offers a new method. According to the experimental results, a correlation in terms of the average Nusselt number and rotating Reynolds number has been established. The equation, Nū = 0.318 Re(r)0.571, has been found valid for a range of the rotating Reynolds number from 2000 to 40000. The average Nusselt number increased with an increase in the rotating speed. Comparison of the results, with the previous studies, have been showed a good agreement with each other.