Heat Transfer Enhancement from Heat Sinks using

Transcription

Heat Transfer Enhancement from Heat Sinks using
ISSN No: 2309-4893
International Journal of Advanced Engineering and Global Technology
I
Vol-03, Issue-06, June 2015
Heat Transfer Enhancement from Heat Sinks using Perforated
Fins: A Review
A. A. Kanaskar‫٭‬
V. M. Kriplani
Student, M.Tech
(Heat Power Engineering)
G.H. Raisoni College of Engineering
Nagpur-16, Maharashtra, India
Professor,
Mechanical Engineering Dept
G.H. Raisoni College of Engineering
Nagpur-16, Maharashtra, India
Abstract - The present review paper contribute the experimental
analysis of the heat transfer growth and the respective pressure
drop below a flat surface embedded with ring shaped or circular
square perforated fins in a rectangular manner. Extended
surfaces (fins) are frequently used as heat exchange appliances to
enhance the heat transfer between the primary surface and
surrounding liquid. Fins are extensively usage as heat exchange
appliances. The fins are widely usage for various industrial
applications. Other modes of fins are rectangular, rounded,
narrowing, ring shaped pin fins or mixture of other geometries
has been used.. Gas turbines of the blades, electronic cooling, and
aerospace application are the few application of short fins. Long
fins have applications where attainment of high heat transfer is
major concerned. Fins provide large total surface area without
the use of a large primary surface area.
Keywords: Perforated
performance.
fins,
Fin
performance,
Thermal
I INTRODUCTION
The augmentation of the heat transfer is very essential to
thermal engineering. The heat transfer from the surface may in
general be enhanced by rising the heat transfer between a
surface and its surrounding by rising the heat transfer area of
the surface. Rectangular fins, square fins and rounded fins are
used for both natural and forced convection of heat transfer.
Other modes of heat exchanging fins, ranging from similarly
shapes, like orthogonal, ring shaped, cylindrical, narrowing or
pin fins, to a mixture of other geometries have been used. In
engineering applications, heat generation can cause
overheating, cooling electronic equipment, heating and cooling
in evaporator, radiator in vehicles, refrigerator, gas turbine
blade, as well as aerospace industry.
P.V. Walke
Professor,
Mechanical Engineering Dept
G.H. Raisoni College of Engineering
Nagpur-16, Maharashtra, India
efficient surface area. They normally use geometrical changes
to the flow channel by compilation inserts or extra
appliances. They promote higher coefficient of heat transfer
by interrupting or to changing the existent flow behavior
except for extended surfaces. Heat transfer enhances by this
method can be accomplished by using these surfaces are
treated, rough, and swirl flow like techniques.
Following are generally used in passive heat transfer
augmentation tools.
a) Ribs b) fins c) pits d) coils of the wire.
C. Compound techniques:
Compound technique is a hybrid technique in which both
active as well as passive techniques are used in combination.
The compound technique needs composite design.
II. REVIEW OF WORK CARRIED OUT
Bayram Sahin , Alparslan Demir [1]carried out the
performance of heat transfer Augmentation with related
pressure drop through a rectangular channel with circular fins
attached to a flat surface. Reynolds number ranges are selected
for this experiment 13500–42,000. They defined the clearance
ratio of space above fins to the height of fin in rectangular
channel.. They found that average Nusselt number and friction
factor enhanced with reducing clearance ratio and interfin
spacing ratio. Rise of the efficiencies varied at middle 1.1 and
1.9 reliant for both the ratio.
.
Various methods of heat transfer augmentation
A. Active method
This system needs external power to the growing of the heat
transfer. There are various specimens of active techniques are
that which produces effect pulsating by cams, reciprocating
pump-piston etc.
B. Passive method
These techniques do not need any external power. Fins are
specimen of passive techniques that are popularly used in
variety of industrial usage to augment the rate of heat transfer
centrally initial surface and ambient liquid. Convective heat
transfer increases the heat transfer rate as to increase the
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Fig1 Experimental set up (1)
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ISSN No: 2309-4893
International Journal of Advanced Engineering and Global Technology
I
Vol-03, Issue-06, June 2015
Ahmad Khoshnevis et al. [2] carried out the study of the
outcome of lateral surface perforation on heat transfer
intensification of a 3-D channel with a ground attached heater.
Hole and slot were two types of perforation are studied.
Ranges of work: Re number 6000-40000 and 0.05 to 0.15 that
is open area perforation ratio. Their results significantly
augmentation in the heat transfer and pressure drop by rising
the perforation area due to disorganizing the thermal traps
distinguish the ribs.
Ahmad Khoshnevis et al. [2] carried out the effect of extended
surface perforation on heat transfer augmentation of a 3-D
channel with a ground attached heater. Two types of
perforation are studied, ie Hole and slot. Ranges of work: Re
number 6000-40000 and open area perforation ratio 0.05 to
0.15 perforation inclination angle: 0<o<45. t. Their results
show significant augmentation in heat transfer and pressure
drop by increases the perforation area due to disorganizing the
thermal traps between the ribs.
M.R Shaeri, M. Yaghoubi [3] carried out on the heat transfer
augmentation and for 3-D liquid flow from grouping of solid
as well as perforated fins that are attached to a horizontal sheet.
Air as effective liquid is used in both the equation like NavierStokes and RNG. Reynolds number ranges are based on the
fin length from 2×104 to 4×104 and Prandtl number Pr=0.71.
Outcome show that fins with longitudinal pores have
remarkable heat transfer augmentation in addition to the
decrease in weight by comparison with solid fins.
E.A.M. Elshafei [4], in this experiment they were performed
on heat transfer from the rounded pin fin attached to a flat
plate. Heat sinks were generally spaced both the solid as well
as perforated rounded pin fins with zigzagged or staggered
combination, attached into a heated base of constant area.
Range of Reynolds no. considered was 3.8x10 6 to 1.65x107.
Perforated fins showing better performance than solid fins in
the heat transfer analysis.
Fig 2 experimental set up (5)
Md. Farhad Ismail et al., [6] in this experiment numerical study
was performed to investigate the turbulent convection heat
transfer on a rectangular plate mounted over a flat surface. The
extended surfaces were of various types of lateral perforations
like rectangular, circular, hexagonal cross sections. RANS
based modified K-W turbulence model is usage to calculate the
fluid flow and heat transfer parameters. Reynolds number
considered from 2000 to 5000 basis on the thickness of the fins.
Shape of lateral perforation has significant effects on the heat
transfer behavior of heat sinks below turbulent flow conditions.
Rectangular perforated fins have the lowest and solid fins getting
higher Nu number. Hexagonal perforated fins have the highest fin
usefulness. Triangular perforated fins have lowest skin friction
coefficient.
O.N. Sara [5] the paper shows that the convective heat transfer
through a rectangular channel with square cross-section fins
mounted below a flat surface. The experimental outcomes
showed that use of square fins may cause to benefit on the
basis of heat transfer augmentation. For higher heat transfer
performance, less inter-fin distance ratio clearance ratio so that
comparatively less Reynolds numbers should be important for
the zigzagged arrangement. They found that the average
Nusselt number enhancing with reducing -fin distance
clearance ratio and inter ratio, the friction factor enhancing
with reducing clearance as well as inter-fin distance ratio.
Fig 3: Three perforation of rounded, hexagonal, square, trilateral
arrangement [6]
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ISSN No: 2309-4893
International Journal of Advanced Engineering and Global Technology
I
Vol-03, Issue-06, June 2015
Rasim Karabacak , Gülay Yakar [7] In this experimentally
studied, diameter holes were 6 mm on each circular fin on a
heating tube that inline arrangement in order to growth of the
heat transfer. The holes invented turbulence in a region nearby
the heating tube surface on the bottom of the fin. They observe
the differences between, perforated finned heaters along with
imperforate finned heater with both additions. Perforated
finned locations are 12% more than the imperforate state in the
Nusselt numbers.
Mohammad Reza Shaeri , Tien-Chien Jen [8],in their merical
investigation they selected fin with greater porosity and with
no change of its porosity, the number were varied to study the
effects of perforation sizes on laminar heat transfer
characteristics of the fins . In this experiment they were using
the Navier–Stokes and energy equations are solved finite
volume with the help of SIMPLE algorithm. Fin with less
perforation is more efficient to increase the heat transfer rate
compared with a fin with more perforations.
Fig 4: Configuration of fin group [8]
Tzer-Ming Jeng, Sheng-Chung Tzeng, [9] carried out the heat
transfer performance analysis with seven square pin fins
fitted to a flat surface with different arrangement are studied.
The outcomes show that lower part facing orientation yields
the less coefficient of heat transfer. It is observed that the
sideward arrangement outcome of the upward one for small
finning factors below 2.7. The optimal heat sink porosity for
both upward and sideward arrangement is around 83%and
91% the addition of surface higher effective for the downward
as well as lower effective for the sideward arrangement.
Ren-Tsung Huang el at., [10] experimentally studied the heat
transfer of a square pin fin of a square fin array in a rectangular
channel with the help of the transient single-blow method.
Longitudinal pitch the relative transverse pitch as well as the
both zigzagged or staggered and line arrangement are the
variable parameters. The performance of the square fins as the
cooling appliances is compared with that of the circular pin
fns. The optimal inter-fin pitches along with the largest Nu
number under the similar pumping power, then
XT = 2 and XL = 1.5 as well as XT = 1.5 and XL = 1.5 for the
arrays in line as well as staggered arrangements. (Relative
longitudinal and transversal pitch were denoted as XT and
XL)
Monoj Baruah el at., [11] they carried out the computational
investigation to assess the heat transfer characteristic of
elliptical pin fins organized in a rectangular duct in a
zigzagged manner. They considered solid as well as
perforated elliptical pin fins with three perforations. They
claimed that by changing the solid elliptical fin into the
perforated elliptical pin fin, the pressure drop decreases by an
average of 12% and heat transfer increases by 23% by
introducing perforations and this performance may be further
improved by increasing the numbers of perforations in
elliptical pin fin.
Kavita H. Dhanawade et at. , [12] experimental to investigate
the heat transfer Enhancement over horizontal flat plate
surface with rectangular fin arrays will lateral square and
circular perforation by force convection .They varied sizes of
perforation as well as Re from 2.1x104 to 8.7x104 .They found
that average of percentage improvement of square perforated
fin is more than that of the fin array of circular perforated fin
of same size. Friction factor slightly increases with increase in
the size of perforation. This type of arrays can becomes for air
cooling of IC engines and other industrial application.
A)
B)
Fig 5 Schematic of the experimental set up. [9]
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ISSN No: 2309-4893
International Journal of Advanced Engineering and Global Technology
I
Vol-03, Issue-06, June 2015
C)
Fig 6.Schematic of the square , circular, solid fin in line arrangement [12
A.B.Ganorkar, V.M.Kriplani [13] studied
whole
performance of suitable designed lateral perforated fins in a
rectangular channel., Different type of perforated fins are
used in the rectangular channel. Effect of perforated fins in a
rectangular channel is observed for other Reynolds numbers.
In respect of the Nusselt numbers as well as heat transfer
coefficient were analyzed. Reynolds number range taken
2500-10000, diameter range of perforated holes 6-10 mm. As
Re number raises the ratio of (Nuperforated/Nusolid) fin increases.
Increase in no. Of holes, the ratio (Nuperforated/Nusolid)
increases. Increase in diameter of
holes the ratio
(Nuperforated/Nusolid) increases. The enhancement of
(Nuperforated/Nusolid) is not significant with increase in no. Of
holes.
Advances in electronic engineering have significant changes
in size and density of high performances chips. Advances in
electronic engineering have significant changes in size and
density of high performances in size and density of high
performances chips. Thermal management of these small, high
flux dissipater chips is an important issue in order to keep them
in order. Active method consists of certain external power for
the augmentation of the heat transfer. Some specimens of
active method cause pulsating by cams, reciprocating pumppiston etc. Passive techniques normally usage surface or
geometrical conversions to the flow channel by compilation
inserts or extra appliances, for few specimens, wire coils,
extended surface appliances, mesh inserts .
References
Bayram Sachin, Alparslan Demir, “Performance analysis of a
heat exchanger having perforated square fins”. Applied Thermal
Engineering28(2008)621-632 .
[2] Ahmad khoshnevis, faramarze talati, maziyar jalaal, esmaeil
esmaeilzadeh, “Heat transfer enhancement of slot & hole shape
perforation in rectangular ribs of a 3-D channel”, 17th Annual
(International) conference on mechanical engineeringISME2009, university of Tehran, Iran.
[1]
[3] M.R. Shaeri, M. Yaghoubi, “Numerical analysis of turbulent
convection heat transfer from an array of perforated fins”,
International Journal of Heat and Fluid flow 30 (2009) 218-228
.
[4] E.A.M. Elshafei, “Natural convection heat transfer from a heat
sink with hollow/perforated circular pin fin”, thermal issues in
emerging technologies, Theta 3, Cairo, Egypt, Dec 19-22nd
2010.
Fig7.Experimental set up [13]
Abdullah H. Alessa, Mohamad I. Al-Widyan. , [14] studied
augmentation of heat transfer from a horizontal rectangular
fin inserted with wedge shaped or triangular perforations
below natural condition. Geometrical measurement of fin and
perforations are the parameters considered. In this experiment,
the heat wastage from the perforated fin for definite distance
of wedge shaped or triangular perforation measurement,
spaces between perforations the outcome in improvement in
heat transfer ended the corresponding solid fin. Growth of the
heat transfer of the perforated fin rises as fin thermal
conductivity is increased. Advances
CONCLUSION
Augmentation of heat transfer is very useful in many
industrial purposes. Very quick heat extraction from heated
surface, lowering material weight as well as cost has become
a greater task for design for heat exchanger equipment.
Modernize of heat exchangers needs efficient techniques
fabrication of heat exchangers to exchange great amount of
heat between extended surfaces and ambient liquid.
729
[5] O.N.Sara, “Performance analysis of rectangular ducts with
staggered square pin fins”, Energy conversion and management
44(2003)1787-1803.
[6] Md. Farhad Ismail,Muhammad Noman Hasan ,Suvash
C.saha“Numerical study of turbulent fluid flow and heat transfer
in lareral perforated extended surfaces”. Energy 64(2014)632639.
[7] Rasim Karabacak,Gulay Yakar,“ Forced convection heat
transfer and pressure drop for a horizontal cylinder with
vertically attached imperforate and perforated circular fins”.
Energy conversion and management 52(2011)2785-2793.
[8] Mohammad Reza Shaeri,Tin-Chien Jen, “The effect
of
perforation Sizes on laminar heat transfer characteristics of an
array of perforated fins
.
[9]
Ren-Tsung Huang, Wen-Junn Sheu,Chi-Chuan Wang,
“Orientation Effect on natural convection convective
performance of square pin fin Heat sinks”. International
Journal of heat and mass transfer51(2008) 2386- 2376
mastransfer51(2008)2386- 2376
[10] Tzer-mingjeng,Sheng-chung Tzeng,“Pressure drop and heat
Transfer of square pin-finarrays in-line and staggere
arrangment”. International Journal of Heat and Mass Transfer
50 (2007) 2364-2375.
[11] Monoj Baruah ,Anupam Dewan, P.Mahanta “Performance of
elliptical Pin heat exchanger with three elliptical perforations”.
Deparmental of Mechanical engg,indian instistute of technology
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ISSN No: 2309-4893
International Journal of Advanced Engineering and Global Technology
I
Vol-03, Issue-06, June 2015
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[12] Kavita H. Dhanwade , Vivek K . Sunnapwar,Hanamant S.Dhanawade,
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(2006) 1990–1997.
[13] A.B. Ganorkar, V.M.Kriplani “Experimental study of Heat transfer
Rate by Using lateral perforated fins in a rectangular channel” MIT
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[14] Abdullah H. Alessa, Mohamad I. Al-Widyan, “Enhancement of
Natural convection heat transfer from a fin by triangular perforation of bases
parallel and toward its tip ” Jordan University of Science and Technology, Irbid,
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