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 based numerical approach for determination of volumetric heat transfer coefficients of modified graphite foams
Date
2020-06-25
Author
GÜRÜF, GÜRŞAH
Solmus, Ismail
BİLEN, Kadir
Bayer, Özgür
Metadata
Show full item record
This work is licensed under a
Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License
.
Item Usage Stats
192
views
0
downloads
Cite This
Graphite-based porous materials are emerging as attractive alternatives to metals for use as heat dissipation elements in thermal management applications. While having several desirable features such as high thermal conductivity and low density, graphite foam heat sinks also tend to have low permeability that can limit transport of working fluid within the component and result in inefficient heat transfer. In order to improve their heat dissipation performance, graphite foams can be modified by channels drilled in various arrangements. However, the heat transfer characteristics of such modified graphite foams are not well characterized. In order to address this problem, we report novel empirical correlations for graphite foams modified in a specific configuration where circular channels with 2 mm diameter are drilled in graphite foam along the flow direction in a staggered arrangement. Then, volumetric heat transfer coefficients between the modified graphite foam and a stream of air are obtained by using transient single-blow technique (TSBT). The transient one-dimensional local thermal nonequilibrium (LTNE) model is employed for determination of the volumetric heat transfer coefficient from experimentally obtained data. Nine different modified graphite foam samples of various L/H ratios are studied in experiments and an empirical correlation of the form Nu(v) = CRea for each sample is derived. Empirical correlations for three different sample lengths (L = 27 mm, 52 mm, 76 mm) at a fixed height are also developed in the form of Nu(v) = CRea(L/H)(b). The novel empirical correlations in question are valid for the Reynolds (Re) number varying from approximately 1000 to 10000. Results show that Nuv generally increases with the increasing value of Re and L at a fixed value of H and the uncertainties associated with Re and Nu(v) are evaluated to be less than 1.3% and 3.6%, respectively. Consequently, we anticipate that the proposed correlations will be useful in reliable design of a new generation of electronic devices.
Subject Keywords
Industrial and Manufacturing Engineering
,
Energy Engineering and Power Technology
URI
https://hdl.handle.net/11511/46547
Journal
APPLIED THERMAL ENGINEERING
DOI
https://doi.org/10.1016/j.applthermaleng.2020.115310
Collections
Department of Mechanical Engineering, Article
Suggestions
OpenMETU
Core
Energy-exergy and economic analyses of a hybrid solar-hydrogen renewable energy system in Ankara, Turkey
ÖZDEN, Ender; Tarı, İlker (Elsevier BV, 2016-04-25)
A hybrid (Solar-Hydrogen) stand-alone renewable energy system that consists of photovoltaic panels (PV), Proton Exchange Membrane (PEM) fuel cells, PEM based electrolyzers and hydrogen storage is investigated by developing a complete model of the system using TRNSYS. The PV panels are mounted on a tiltable platform to improve the performance of the system by monthly adjustments of the tilt angle. The total area of the PV panels is 300 m(2), the PEM fuel cell capacity is 5 kW, and the hydrogen storage is at ...
PHPA as a Frictional Pressure Loss Reducer and Its Pressure Loss Estimation
Ozbayoglu, M. E.; Ercan, C. (Informa UK Limited, 2010-01-01)
This article analyzes the performance of a liquid polymer emulsion containing partially hydrolyzed polyacrylamide/polyacrylate (PHPA) copolymer as a circulating system pressure loss (drag) reducer. Straight cylindrical pipe flow experiments were performed at different concentrations of solutions for measuring frictional pressure losses. Comparison of measured and theoretical frictional pressure loss values showed that as the PHPA concentration increased, considerable drag reduction (as high as 60%) was achi...
ELECTROKINETICS OF OXIDIZED COAL
SARIKAYA, M; OZBAYOGLU, G (Elsevier BV; 1990-01-01)
Electrokinetic measurements were carried out in order to determine the properties of oxidized coal surfaces over a wide pH range both in the presence and absence of various metal ions and flotation collectors. It was found that polyvalent cations, such as Fe++, Fe+++ and Al+++ decreased the zeta potential to zero and then reversed the charge. In the presence of cationic collectors, the negative value of zeta potential of oxidized coal was driven positive, below 9.3 to 10.9 depending on the type and concentr...
Integrated analysis of pressure response using pressure-rate convolution and deconvolution techniques for varied flow rate production in fractured formations
Al-Rbeawi, Salam (Elsevier BV, 2018-03-01)
This paper introduces an integrated analysis for pressure transient behavior of conventional and unconventional multi-porous media reservoirs considering varied flow rate conditions. It focuses on the applications of pressure-rate convolution and deconvolution techniques for analyzing pressure records of homogenous single porous media, double porous media, and triple porous media reservoirs. The tasks covered in this paper are: Deconvloving pressure response, characterizing and developing analytical models ...
Effect of design and operating parameters on the thermal performance of aluminum flat grooved heat pipes
Alijani, Hossein; Cetin, Barbaros; Akkuş, Yigit; Dursunkaya, Zafer (Elsevier BV, 2018-03-05)
Four aluminum flat grooved heat pipes with groove widths of 0.2, 0.4, 0.8 and 1.6 mm are fabricated and the effect of filling ratio on the thermal performance is experimentally studied for four different heat flux values of 2.1, 3.2, 4.2 and 5.3 W/cm(2). An optimum filling ratio corresponding to each heat flux is determined where the heat pipe has the best thermal performance. Thermal performance of the heat pipes are evaluated using three indicators: (i) the temperature difference between the heat source a...
Citation Formats
IEEE
ACM
APA
CHICAGO
MLA
BibTeX
G. GÜRÜF, I. Solmus, K. BİLEN, and Ö. Bayer, “Experimental based numerical approach for determination of volumetric heat transfer coefficients of modified graphite foams,”
APPLIED THERMAL ENGINEERING
, pp. 0–0, 2020, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/46547.