Show/Hide Menu
Hide/Show Apps
Logout
Türkçe
Türkçe
Search
Search
Login
Login
OpenMETU
OpenMETU
About
About
Open Science Policy
Open Science Policy
Open Access Guideline
Open Access Guideline
Postgraduate Thesis Guideline
Postgraduate Thesis Guideline
Communities & Collections
Communities & Collections
Help
Help
Frequently Asked Questions
Frequently Asked Questions
Guides
Guides
Thesis submission
Thesis submission
MS without thesis term project submission
MS without thesis term project submission
Publication submission with DOI
Publication submission with DOI
Publication submission
Publication submission
Supporting Information
Supporting Information
General Information
General Information
Copyright, Embargo and License
Copyright, Embargo and License
Contact us
Contact us
Experimental investigation of single phase liquid flow and heat transfer in multiport minichannels
Download
index.pdf
Date
2013
Author
Altınöz, Mesru
Metadata
Show full item record
Item Usage Stats
303
views
265
downloads
Cite This
This thesis aims to experimentally investigate pressure drop and heat transfer characteristics of single phase water flow in rectangular minichannels. The small channels are an area of interest in heat transfer field since 1970’s owing to their enhanced heat transfer characteristics. However, the heat transfer and pressure drop characteristics of these channels are not fully established as there is a wide number of studies in literature showing inconsistent results with each other. In order to investigate this matter further, an experimental set-up is designed and constructed. Laminar region is considered during the experiments because the flow inside minichannels is generally laminar due to pressure drop considerations. Additionally, constant heat flux condition is selected to stimulate cooling with internal flow in minichannels. In the scope of this study, three minichannels with different hydraulic and different port numbers diameters were examined. The results are presented in terms of Poiseulle numbers and average Nusselt numbers. Generally, average Nusselt number results and Poiseuille number results showed a good agreement with constant Po theory and constant Nu theory excluding developing effects and experimental errors. On the other hand, developing effects are found to be increasing as hydraulic diameter decreases. Similarly, constant Nu value showed a decrease with increasing hydraulic diameter. The small scale heat transfer correlations and conventional heat transfer correlations are compared with experimental resuts. The conventional correlations followed the trend of results precisely but predictions of correlations overestimated most of the results. When a correction factor is applied, several correlations predicted almost all results within 11%. Small scale correlations showed agreement with a few results but mostly overestimated the Nu results. No early transition were observed for Reynolds number smaller than 1800. No signs of Poiseuille number or average Nusselt number dependency on Reynolds number were observed considering developing effects and uncertainty values.
Subject Keywords
Heat
,
Heat
,
Laminar flow.
,
Single-phase flow.
,
Fluid dynamics.
URI
http://etd.lib.metu.edu.tr/upload/12616710/index.pdf
https://hdl.handle.net/11511/23218
Collections
Graduate School of Natural and Applied Sciences, Thesis
Suggestions
OpenMETU
Core
Improving flow structure and natural convection within fin spacings of plate fin heat sinks
Özet, Mehmet Erdem; Tarı, İlker; Department of Mechanical Engineering (2015)
The main objectives of this thesis are to numerically investigate the previously observed recirculation zones and longitudinal vortices that occur in low fin height plate finned horizontal heat sinks and to improve the flow structures and heat transfer in these zones using various approaches with the help of simulations performed using commercially available CFD software. The approaches used for improvements are replacing the outer most fins with higher ones, introducing gaps on the length of the fins in va...
EXPERIMENTAL AND NUMERICAL STUDY ON HEAT TRANSFER PERFORMANCE OF SQUARE, CYLINDRICAL AND PLATE HEAT SINKS IN EXTERNAL TRANSITION FLOW REGIME
İnci, Aykut Barış; Bayer, Özgür (2019-01-01)
Geometrical optimization of heat sinks with square, cylindrical and plate fins for heat transfer increase is numerically analyzed in transition regime external flow. The relations between the thermal characteristics of fins and boundary conditions such as free-stream velocity are investigated. Experimental studies are performed by using manufacturable fins to validate the numerical model. Heat transfer correlations are derived in order to determine average heat transfer coefficients over a certain range of ...
Analysis of Transient Laminar Forced Convection of Nanofluids in Circular Channels
Sert, İsmail Ozan; Sezer Uzol, Nilay; Güvenç Yazıcıoğlu, Almıla; Kakaç, Sadık (2012-11-15)
In this study, forced convection heat transfer Characteristics of nanofluids are investigated by numerical analysis of incompressible transient laminar flow in a circular duct under step change in wall temperature and wall heat flux. The thermal responses of the system are obtained by solving energy equation under both transient and steady-state conditions for hydrodynamically fully developed flow. In the analyses, temperature dependent thermo-physical properties are also considered. In the numerical analys...
3-D numerical simulations of fluid flow and heat transfer in various micro conduits
Turgay, Metin Bilgehan; Güvenç Yazıcıoğlu, Almıla; Department of Mechanical Engineering (2017)
In this work, it is aimed to investigate the effect of roughness geometrical properties and configurations on laminar flow and heat transfer characteristics in microchannels, numerically. For this purpose, two-dimensional parallel plate, and three-dimensional trapezoidal microchannels with different roughness properties are modeled along with the smooth ones. Fluid flow and heat transfer simulations are conducted with COMSOL Multiphysics. Roughness is modeled as triangular obstructions on one of the plates ...
EXPERIMENTAL INVESTIGATION OF HEAT TRANSFER AND PRESSURE DROP OVER RECTANGULAR PROFILE FINS PLACED IN A SQUARE CHANNEL
Aylı, Ece; Kıyıcı, Fırat; Bayer, Özgür; ARADAĞ ÇELEBİOĞLU, SELİN (2014-06-19)
In this study, with the help of a fan, fully developed turbulent flow conditions are experimentally obtained to investigate the heat transfer and pressure drop characteristics of rectangular fins. Fins with different geometries are placed to the bottom surface of a square shaped channel. Finned test pieces are heated by constant heat flux and other parts are kept as well insulated. The effect of fin height to the heat transfer coefficient is investigated by performing experiments. Temperature distributions,...
Citation Formats
IEEE
ACM
APA
CHICAGO
MLA
BibTeX
M. Altınöz, “Experimental investigation of single phase liquid flow and heat transfer in multiport minichannels,” M.S. - Master of Science, Middle East Technical University, 2013.