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7/25/2019 Heat Transfer Lab 1
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Heat Transfer MECE 3930U
Lab 1:
Heat Conduction Unit
Lab Group:
Date of Lab: January !" 01#
Due Date: $ebruary %" 01#
&a'e (tudent )D (i*natureEric McCor'ic+ 100! 303#Matt,e- Le.ins 100! 03/#Ty er Le-is 100! !Cody 2a ton 100! 10#3
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Contents)ntroduction
T,eoretica 4ac+*round and 5pp ication
E6peri'enta Unit and 7rocedure
E8uip'ent
7rocedure
esu ts and Discussion
E8uations
Tabu ated DataConc usion
&o'enc ature
eferences
5ppendi6
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1
IntroductionT,e ob ecti.e of t,is ab is to in.esti*ate i'portant aspects of conduction ,eat transfer
Measure'ents -i be 'ade to e6p ore t,e properties of t,er'a conducti.ity and te'perature
c,an*es for bot, inear and radia conduction cases
T,er'a conduction is described as t,e transfer of ener*y fro' 'ore ener*etic partic es
to ess ener*etic partic es due to t,e partic es interactions -it, one anot,er )n a stationary
'ediu'" t,is causes a te'perature *radient to e6ist in t,e 'ediu' Heat transfer e6ists in
.irtua y a en*ineerin* app ications" t,erefore" it is i'portant to ,a.e an understandin* of t,e
'ec,anics in.o .ed -it, t,er'a conducti.ity
Theoretical Background and ApplicationT,er'a conduction is t,e transfer of ener*y" in t,e for' of ,eat" fro' areas of ,i*,er
ener*y concentration to areas of o-er concentration T,e 'et,ods in -,ic, ener*y transfers
.ary dependin* on t,e p,ysica state of t,e 'ediu' in.o .ed $or *aseous and i8uid 'ediu's"
t,e transfer of ener*y is due to co isions and diffusion of 'o ecu es durin* rando' 'otion $or
so id 'ediu's" t,e transfer of ener*y is due to .ibrations in t,e 'o ecu ar attice and by ener*y
transported by free e ectrons 'o.in* fro' one 'o ecu e to anot,er
$ourier;s a- of ,eat conduction describes t,e re ations,ip bet-een t,e rate of ,eat
conduction and .arious properties of t,e 'ediu' as:
Rateof Heat Conduction ( Area )(Tempurature Difference )
Thickness
T,er'a conducti.ity is t,e abi ity for a 'ateria to conduct ,eat T,is .ariab e" denoted as k " is
dependent on t,e 'ediu' on -,ic, t,e t,er'a conduction is occurrin* 4y usin* t,er'a
conducti.ity" t,e e8uation for t,e rate of ,eat condition is:
Q cond = kA dT dx
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Heat conduction occurs in t,e direction of decreasin* te'perature Due to t,is" t,e
te'perature *radient"dT dx " beco'es ne*ati.e -it, t,e positi.e 6
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3
Experimental Unit and Procedure
Equipment
T,e e8uip'ent in.o .ed -it, t,e co'p etion of t,is aboratory is as fo o-s:
T,er'a Conduction Unit
1 Heat conduction in 3 .arious p ane -a sHeat conduction in a cy inder
3 Contro and disp ay unit/ Data cab e! 7o-er cab e# Coo in* -ater feed
2ater return syste'% Mains po-er
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T,ree Types of )nserts
1 4rass" !'' Dia'eter" 30'' Len*t,(tain ess (tee 1 /30!" !'' Dia'eter" 30'' Len*t,
3 4rass" 1!'' Dia'eter" 30'' Len*t,
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!
Cy indrica Heat Conduction Unit
1 )nsu ated ,ousin*Dis+
3 Heater / Coo er =copper pipe>! (i6 te'perature 'easurin* points
Procedure
T,e ,eat conduction unit -as setup as s,o-n in $i*ure 1 of t,e aboratory 'anua Co d
-ater -as supp ied to t,e unit usin* t,e ,oses )nsert 1 -as insta ed and t,e coo in* -ater f o-
rate -as ad usted to appro6i'ate y 1+*?, to ensure t,at a ,eater po-er of 90 2 at a te'perature
difference of 90@C T,e unit -as turned on and t,e te'perature drop -as set usin* t,e po-er
settin* on t,e contro and unit disp ay T,e unit -as a o-ed to reac, a steady state condition"
t,is occurs -,en t,e indi.idua 'easurin* points are stab e and unc,an*in* T,e po-er supp ied
to t,e unit and t,e te'perature at t,e indi.idua 'easurin* points -ere recorded T,is process
-as repeated t,ree 'ore ti'es for t,e t-o ot,er inserts" and once a*ain for t,e radia unit
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#
Results and Discussion
Equations
Heat conduction in a -a is described by $ourier;s La-" -,ic, is e6pressed as:
Q cond = kA dT dx
$or t,e co'posite -a s,o-n in $i*ure # of t,e ab 'anua " t,e ,eat f o- is described as:
1st Layer: Q= K 1 A(T 1 T 2 )
L1
nd Layer: Q= K 2 A(T 2 T 3 )
L2
&t, Layer: Q= K n A(T n T n+1 )
Ln
T,e ,eat f o- fro' t,e o.era difference is found by t,e fo o-in* e8uation:
Q= A(T 1 T n+1 ) L1k 1
+ L2k 2
+ Lnk n
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Tabulated Data
Tab e 1: Heat Conduction in a 7 ane 2a =)nsert A1 -it, 3 Te'perature Measure'ent 7oints>
Te'perature
Measure'ent
7oints
Materia of Measure'ent
(ection
4rass 4rass 4rass
Dia'eter =''> ! ! !T,eoretica Conducti.ity at
0@C =-?'B >
113 113 113
Measured Heatin* 7o-er =2> #3 !Distance
=''>
Measured
Te'perature
=@C>
Te'p Difference in
= >
T,er'a Conducti.ity
=2?'B >
1 < T 1 = 73.5 <
Te'perature
Measure'ent7oints
Materia of Measure'ent
(ection
4rass (tain ess
(tee
4rass
Dia'eter =''> ! ! !T,eoretica Conducti.ity at
0@C =-?'B >
113 1! 113
Measured Heatin* 7o-er =2> //Distance
=''>
Measured
Te'perature
=@C>
Te'p Difference in
= >
T,er'a Conducti.ity
=2?'B >
1 < T 1 = 103.8 <
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%
10 T 2 = 102.5
3 0 T 3 = 98.6
Contact 7oint
1
! T 4 =
Contact 7oint !! T 6 =
#0 T 7 = 28.6
% 0 T 8 = 26.6
9 %0 T 9 = 23.5
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9
Tab e 3: Heat Conduction in a 7 ane 2a =)nsert A3 -it, &o Te'perature Measure'ent 7oints>
Te'perature
Measure'ent
7oints
Materia of Measure'ent
(ection
4rass 4rass 4rass
Dia'eter =''> ! 1! !T,eoretica Conducti.ity at
0@C =-?'B >
113 113 113
Measured Heatin* 7o-er =2> ! 1Distance
=''>
Measured
Te'perature
=@C>
Te'p Difference in
= >
T,er'a Conducti.ity
=2?'B >
1 < T 1 = 85.3 <
Te'perature
Measure'ent
7oints
Materia of Measure'ent
(ection
4rass
Dia'eter =''> 1 ?110T,eoretica Conducti.ity at
0@C =-?'B >
113
Measured Heatin* 7o-er =2> #/Distance
=''>
Measured
Te'perature
=@C>
Te'p Difference in
= >
T,er'a Conducti.ity
=2?'B >
1 < T 1 = 46.8