RMIK_T3
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Transcript of RMIK_T3
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7/23/2019 RMIK_T3
1/3
Romero Moreno Itzel Karina
Tarea No.3
Una rebanada de mantequilla de 34mm de grueso se encuentra inicialmente a 5C. Se
coloca sobre una superficie aislada y expuesta al aire a 30 C. El coeficiente de
transferencia conectia de calor es !."3#$m%&. 'as propiedades de la mantequilla son lassiguientes( &)0.*+%#$m &, calor espec-fico)%%50$&g & y densidad) ++!& g$m3.Calcule
la temperatura *0mm de ba/o de la superficie despus de 30min,*1, *1 30min, %1, %1
30min, 31, 31 30min, 41, 41 30min y 51.
997Kg
m32250
J
Kg K
=8.56108
m2
s
= K
CP=0.192
W
m K
n=
(3410 )m34m
=
24
34=0.71
m= K
h Xi=
0.192 W
mK
7.83W
m2
0.034m
=0.71
t=30min
= t
xi=8.5610
8 m2
s 1800 s
(0.034m)2 =0.13
Y=T
1T
T1T0;T=T
1[Y(T1T0 ) ]
T=30 [.50 (305 )]=17.5
t=60min
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7/23/2019 RMIK_T3
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= t
xi=8.5610
8m2
s3600 s
(0.034m)2 =0.27
T=30
[.49
(30
5
)]=17.75
t=90min
= t
xi=8.5610
8 m2
s 5400 s
(0.034m)2 =0.4
T=30 [. 48(305)]=18
t=120min
= t
xi=8.5610
8m2
s7200 s
(0.034m)2 =0.53
T=30 [. 46 (305)]=18.5
t=150min
= t
xi=8.5610
8m2
s9000 s
(0.034 m)2 =0.67
T=30 [. 44 (305 )]=19
t=180min
= t
xi=8.56108 m
2
s 10800 s
(0.034m)2 =0.80
T=30 [. 42(305)]=19.5
t=210min
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= t
xi=8.5610
8 m2
s 12600 s
(0.034m)2 =0.93
T=30
[.39
(30
5
)]=20.25
t=240min
= t
xi=8.5610
8 m2
s 14400 s
(0.034m)2 =1.07
T=30 [.37 (305)]=20.75
t=270min
= t
xi=8.5610
8 m2
s 16200s
(0.034m)2 =1.2
T=30 [.34 (305)]=21.5
t=300min
= t
xi=8.5610
8 m2
s 18000 s
(0.034m)2 =1.33
T=30 [.32 (305)]=22