dc.contributor.advisor | Çetin, Barbaros | |
dc.contributor.author | Kurt, Cem | |
dc.date.accessioned | 2019-10-10T06:02:20Z | |
dc.date.available | 2019-10-10T06:02:20Z | |
dc.date.copyright | 2019-09 | |
dc.date.issued | 2019-10 | |
dc.date.submitted | 2019-10-07 | |
dc.identifier.uri | http://hdl.handle.net/11693/52535 | |
dc.description | Cataloged from PDF version of article. | en_US |
dc.description | Thesis (M.S.): Bilkent University, Department of Mechanical Engineering, İhsan Doğramacı Bilkent University, 2019. | en_US |
dc.description | Includes bibliographical references (leaves 56-60). | en_US |
dc.description.abstract | Flat-grooved heat pipes (FGHP) are widely used in many applications from
thermal management of electronic devices to space industry due to their robustness
and ability of dissipating heat from the system effectively and reliably. FGHP
is basically a container with micro grooves on the inner surfaces, and essentially
a bridge that can transfer large amount of thermal energy between a heat source
and a sink with small temperature differences by utilizing the phase change mechanism
of the working
uid. Heat source evaporates the working
uid in the one
end of the grooves, and due to the pressure difference, the composed vapor
ows
to the heat sink region in the other end. Then the vapor condenses back into the
grooves before it
ows to the evaporation region by the capillary force and repeat
the cycle. Mathematical modeling of heat transfer and
uid
ow of FGHP's is
crucial to understand the effects of many parameters (dimensions, groove shape,
working
uid filling ratio, material types) on their operational limits in order to
design case-specific heat pipes. In the literature, many models are presented with
some simplifications and assumptions. In this thesis, a computational methodology
is proposed that models the heat transfer and
uid
ow fully in 3D for
the first time, by using COMSOL Multiphysics R
via LiveLinkTM for MATLABR
interface. Combining the
exibility of script environment of MATLAB with the
benefits of using energy and momentum solvers of a commercial software gives a
powerful and practical tool that can overcome great difficulties if this modeling
was to be done in a CFD software or an in-house code alone. In the presented
model, radius of curvature (R) variation of the working
uid in the groove, temperature
gradient of the groove wall (Tw), and vapor temperature (Tv) are the
essential working parameters of a heat pipe that re
ects the efficiency. In this
methodology, these variables are estimated initially, and are calculated by a set
of inter-bedded and subsequent iterations. The momentum equations are solved
for the iteration of R, Tw is iterated by solving the energy equations, and lastly
Tv is calculated by the secant method using the conservation of mass. Depending
on the values of the variables, the solution domain is regenerated and the phase
change boundary conditions are recalculated at each iteration. The presented
model is compared with the literature for validation. Then, a parametric study
for investigating the effect of groove depth on the performance of a
at-grooved
heat pipe is conducted. Different power of heat sources are used for determining
the dry-out in the grooves. | en_US |
dc.description.statementofresponsibility | by Cem Kurt | en_US |
dc.format.extent | xiii, 91 leaves : charts (some color) ; 30 cm. | en_US |
dc.language.iso | English | en_US |
dc.rights | info:eu-repo/semantics/openAccess | en_US |
dc.subject | Flat-grooved heat pipe | en_US |
dc.subject | Multidimensional heat transfer and fluid flow | en_US |
dc.subject | Modeling | en_US |
dc.title | Three-dimensional modeling of heat transfer and fluid flow in a flat-grooved heat pipe | en_US |
dc.title.alternative | Düz oluklu ısı borularında akışın ve ısı transferinin üç-boyutlu modellenmesi | en_US |
dc.type | Thesis | en_US |
dc.department | Department of Mechanical Engineering | en_US |
dc.publisher | Bilkent University | en_US |
dc.description.degree | M.S. | en_US |
dc.identifier.itemid | B120357 | |