مجال
التميز
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إبداع علمي وتميز دراسي وبحثي
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جوائز التكريم:
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الجائزة (1):
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مسمى الجائزة:
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Best Paper Award
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الجهة المانحة:
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COMSOL
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تاريخ منح الجائزة:
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24/10/2013
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مجال التكريم:
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Best Paper titled: “Optimal Heat Sink Fin and Cold
Lid Heights for Liquid Immersed Servers”
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البحوث المنشورة
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البحث (1):
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عنوان البحث:
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The
Effect of CPU Location in Total Immersion of Microelectronics
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رابط إلى البحث:
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Click here
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تاريخ النشر:
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20/04/2014
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موجز عن البحث:
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Meeting the growth in demand for digital
services such as social media, telecommunications, and business and cloud
services requires large scale data centres, which has led to an increase in
their end use energy demand. Generally, over 30% of data centre power is
consumed by the necessary cooling overhead. Thus energy can be reduced by
improving the cooling efficiency. Air and liquid can both be used as cooling
media for the data centre. Traditional data centre cooling systems use air,
however liquid is recognised as a promising method that can handle the more
densely packed data centres. Liquid cooling can be classified into three
methods; rack heat exchanger, on-chip heat exchanger and full immersion of
the microelectronics. This study quantifies the improvements of heat transfer
specifically for the case of immersed microelectronics by varying the CPU and
heat sink location. Immersion of the server is achieved by filling the gap
between the microelectronics and a water jacket with a dielectric liquid which
convects the heat from the CPU to the water jacket on the opposite side. Heat
transfer is governed by two physical mechanisms, which is natural convection
for the fixed enclosure filled with dielectric liquid and forced convection
for the water that is pumped through the water jacket. The model in this
study is validated with published numerical and experimental work and shows
good agreement with previous work. The results show that the heat transfer
performance and Nusselt number (Nu) is improved by 89% by placing the CPU and
heat sink on the bottom of the microelectronics enclosure.
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البحث (2):
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عنوان البحث:
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Cooling System
Analysis for a Data Center using Liquid Immersed Servers
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رابط إلى البحث:
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Click here
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تاريخ النشر:
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01/09/2014
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موجز عن البحث:
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Data centers are
large consumers of power, of which a large proportion is spent on removing
the heat generated by the semiconductors inside IT servers. This paper
develops a full analysis of the cooling system when servers are immersed in a
dielectric liquid and water is used to transport the heat outside of the data
center. The analysis combines empirical curve fits and flow analysis with
computational fluid dynamics (CFD) simulations of liquid immersed servers
placed in parallel in a rack of a data center. The liquid immersed server
concept is based on a dielectric liquid that is in direct contact with the
semiconductor components to improve heat rejection. The heat generated from
the microelectronics is naturally convected, via buoyancy, in the dielectric
liquid to a cold plate on the opposing side. The cooling system of the data
center in this study consists of a dry air cooler and a liquid-to-liquid
buffer heat exchanger. It was found that the power usage effectiveness (PUE)
is as low as 1.08 for the cooling system. The results also show that the PUE
is affected by the server-rack occupancy and can increase by 26% as occupancy
drops by 80%, thus the better the server-rack occupancy, the better the PUE.
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المؤتمرات العلمية:
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المؤتمر (1):
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عنوان المؤتمر:
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8th
International Conference on Multiphase Flow
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تاريخ الإنعقاد:
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20-22/04/2015
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مكان
الإنعقاد:
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Valencia, Spain
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طبيعة المشاركة:
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Paper presentation
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عنوان المشاركة:
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Effect of processor layout on the thermal performance
of fully immersed liquid-cooled microelectronics
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ملخص المشاركة:
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The natural convection cooling system of a
fully immersed server in a dielectric liquid is analysed numerically. In the
present case study, the dielectric liquid represents the working fluid, which
fully submerges the server inside its sealed capsule. The capsule includes
the normal microelectronic components found in traditional air-cooled
servers, but submerged in a dielectric fluid, which can be modelled as a
saturated porous media using a Darcy flow regime. This study focuses on the
role of spatial parameters on the thermal behaviour of convective heat
transfer, in particular the locations and separations of two heat sources
representing two central processing units (CPUs). The flow and heat transfer
characteristics is analysed for a range of modified Rayleigh number between
0.5 and 300. Stokes equations are solved numerically to model the physical
domain using successive over relaxation and time marching techniques. From
the obtained correlation, the thermal behaviour is strongly influenced by the
modified Rayleigh number. In addition, it is worth mentioning, the CPU
in-between distance, S, is seen to be more influential than space-to-edge,
Ly. For that, the average Nusselt number of the upper core is increased
sharply.
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المؤتمر (2):
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عنوان المؤتمر:
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8th
Saudi Student conference
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تاريخ الإنعقاد:
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31/01 –
01/02/2015
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مكان
الإنعقاد:
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London, UK
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طبيعة المشاركة:
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Poster
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عنوان المشاركة:
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Investigation of processor location of immersed server
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ملخص المشاركة:
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High demand on digital services such as
social media, telecommunications, banks and cloud services requires a
powerful data centres. This has led to increase of data centre energy. Over
30% of data centre power is consumed by cooling of data centre. So reducing
the power consumed by cooling means reducing the power required for data
centre. Air and liquid can be used as cooling media for the data centre.
Traditional data centre cooling system uses air, however liquid is recognised
as a promising method that can handle a high dense data centre. Liquid
cooling can be classified into three methods; rack heat exchanger, on a chip
heat exchanger and immersed server. The interest of this study is to
investigate the improvements of heat transfer in immersed server by varying
the CPU and heat sink position. The immersed idea is that the sever is filled
with dielectric liquid and the heat from the CPU conducted to the heat sink
made of copper then the liquid convects the heat to cold plate that placed on
the opposite of the heat sink. There are two physical models which are
natural convection for the dielectric liquid and forced convection for the
water passed through cold plate channel.
The model in this study is validated with published numerical and
experimental work and model shows a good agreement with previous work. The
results show that the heat transfer performance and Nusselt number (Nu) has a
significant improvement by placing the CPU and heat sink on the bottom of the
server.
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المؤتمر (3):
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عنوان المؤتمر:
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17th
International Conference on Heat Transfer and Applications
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تاريخ الإنعقاد:
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April 2015
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مكان
الإنعقاد:
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Boston, USA
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طبيعة المشاركة:
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Paper presentation
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عنوان المشاركة:
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The Effect of CPU Location in Total
Immersion of Microelectronics
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ملخص المشاركة:
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Meeting
the growth in demand for digital services such as social media,
telecommunications, and business and cloud services requires large scale data
centres, which has led to an increase in their end use energy demand.
Generally, over 30% of data centre power is consumed by the necessary cooling
overhead. Thus energy can be reduced by improving the cooling efficiency. Air
and liquid can both be used as cooling media for the data centre. Traditional
data centre cooling systems use air, however liquid is recognised as a
promising method that can handle the more densely packed data centres. Liquid
cooling can be classified into three methods; rack heat exchanger, on-chip
heat exchanger and full immersion of the microelectronics. This study
quantifies the improvements of heat transfer specifically for the case of
immersed microelectronics by varying the CPU and heat sink location.
Immersion of the server is achieved by filling the gap between the
microelectronics and a water jacket with a dielectric liquid which convects
the heat from the CPU to the water jacket on the opposite side. Heat transfer
is governed by two physical mechanisms, which is natural convection for the
fixed enclosure filled with dielectric liquid and forced convection for the
water that is pumped through the water jacket. The model in this study is
validated with published numerical and experimental work and shows good
agreement with previous work. The results show that the heat transfer
performance and Nusselt number (Nu) is improved by 89% by placing the CPU and
heat sink on the bottom of the microelectronics enclosure.
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المؤتمر (4):
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عنوان المؤتمر:
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7th Saudi
Student conference
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تاريخ الإنعقاد:
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01-02/02/2014
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مكان
الإنعقاد:
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Edinburgh,
UK
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طبيعة المشاركة:
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Poster
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عنوان المشاركة:
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Computational
analysis for an optimum heat sink fin and cold plate heights for liquid
immersed server
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ملخص المشاركة:
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Using
cloud computing, internet applications and telecommunication has led to an
increase in the number of data centres that are used to store and process
data. These powerful systems consume huge amounts of power and generate waste
heat. Cooling these data centre is important for their efficient function.
Air and liquid cooling techniques are used to cool data centres. Air cooling
causes hot and cold streams to mix, which leads to inefficiencies, generates
dust and causes fan noise. Methods can
be applied that use the alternative of liquid cooling for the data centre
equipment. Liquids have greater
capacity for handling higher heat densities and are generally more efficient
than air cooling system.
Immersion
of the server inside a dielectric liquid with good thermal expansion is one
such liquid cooling approach that is used in this study.
Thirty
model simulations of immersed server have been carried out to determine the
optimum heat sink fin height and cold plate height that provides great heat
transfer with lowest Tcase. The best fin height and cold plate height that
changes in this study is found to reduce the CPU temperature by 18 K.
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المؤتمر (5):
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عنوان المؤتمر:
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COMSOL
Conference
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تاريخ الإنعقاد:
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Oct 2013
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مكان
الإنعقاد:
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Rotterdam
, Netherland
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طبيعة المشاركة:
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Paper
presentation
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عنوان المشاركة:
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Optimal
Heat Sink Fin and Cold Lid Heights for Liquid Immersed Servers
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ملخص المشاركة:
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The
system in this study is a closed server filled with Novac dielectric cooling
liquid. The heat is generated by the CPU that conducts to the fin which helps
to dissipate the heat. The heat convects via the dielectric liquid to the
cold lid, where the cold lid is placed on the opposite side. The aim of this
study is to find out the optimum value of the fin height and the cold lid
height. A mesh accuracy investigation was conducted. The model set up in this
work is validated with published experiment. An Optimal Latin Hypercube
design (OLH) of experiment used to select 30 cases to be investigated.
Genetic Algorithm (GA) was applied to find the optimum solution. A 3D model
of COMSOL is used to find that the optimum fin height is 23.9 mm and the cold
lid height is 30 mm. This dropped 22% of the temperature of the Tcase.
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المؤتمر (6):
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عنوان المؤتمر:
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Data
Centre Transformation Conference
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تاريخ الإنعقاد:
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26-27/06/2012
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مكان
الإنعقاد:
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Leeds,
UK
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طبيعة المشاركة:
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Poster
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عنوان المشاركة:
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Model
analyses for optimum fin heat sinks for liquid immersion
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ملخص المشاركة:
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Increasing
the number of users for digital services such as telecommunication, social
media, banks, etc. required powerful data centres to deal with them. Since
more power means more heat, a major share of data centre energy consumed by
cooling of data centre. The cooling of data centre can be achieved by either
air or liquid. Traditional data centre uses air, however liquid can handle a
high density data centre. There are three techniques of using liquid which
are back rack heat exchanger, on server or on chip heat exchanger and
immersed server. In immersed sever the fluid that is used is dielectric
liquid which is in direct contact with semiconductors. In this study the
investigation is carried out for a server immersed, and the results shows
that the heat transfer improved by either reducing the lid height or
increasing the fin height.
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المؤتمر (7):
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عنوان المؤتمر:
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6th Saudi
Student conference
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تاريخ الإنعقاد:
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11-14/10/2012
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مكان
الإنعقاد:
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London,
UK
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طبيعة المشاركة:
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Paper
presentation
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عنوان المشاركة:
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3D analyses for
optimum fin plate thickness of heat sink immersed inside server
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ملخص المشاركة:
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The
high demand of using the information technology requires more powerful data
centre. Since more power means more heat load, cooling data centre became an
important issue to cope with data centre heat requirements. Two main
techniques are used for data centre cooling, which are air and liquid
cooling. Immersed server inside dielectric liquid is one of the liquid
cooling methods that have been used in this study. In present study the
server includes CPU which generates 130w of the heat load. The liquid between
the CPU and cold plate moves due to the density variation. The plate fin heat
sink is used to boost the heat dissipation from the CPU to the cold plate.
Adding more fins increases the surface area and decrease the heat transfer
coefficient, in contrast fewer fins array increase the heat transfer
coefficient, but decrease the fin surface area. Therefore, there must be an optimum fin
thickness that can provide best heat transfer. This study focused on 3D model
using COMSOL to find out the best fin thickness of immersed heat sink. While
the space between the fin kept constant at 1.5 mm, and the best fin thickness
has been found is 0.9mm.
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