Chips of width L = 15 mm on a side are mounted to asubstrate that is installed in an enclosure whose wallsand air are maintained at a temperature of T s u t = 25 ° C .The chips have an emissivity of ∈ = 0.60 and a maximum allowable temperature of T s = 85 ° C . (a) If heat is rejected from the chips by radiation andnatural convection, what is the maximum operatingpower of each chip? The convection coefficientdepends on the chip-to-air temperature differenceand may be approximated as h = C ( T s − T ∞ ) 1 / 4 , where C = 4.2 W / m 2 ⋅ K 5 / 4 . (b) If a fan is used to maintain airflow through theenclosure and heat transfer is by forced convection, with h = 250 W / m 2 ⋅ K , what is the maximum operating power?
Chips of width L = 15 mm on a side are mounted to asubstrate that is installed in an enclosure whose wallsand air are maintained at a temperature of T s u t = 25 ° C .The chips have an emissivity of ∈ = 0.60 and a maximum allowable temperature of T s = 85 ° C . (a) If heat is rejected from the chips by radiation andnatural convection, what is the maximum operatingpower of each chip? The convection coefficientdepends on the chip-to-air temperature differenceand may be approximated as h = C ( T s − T ∞ ) 1 / 4 , where C = 4.2 W / m 2 ⋅ K 5 / 4 . (b) If a fan is used to maintain airflow through theenclosure and heat transfer is by forced convection, with h = 250 W / m 2 ⋅ K , what is the maximum operating power?
Solution Summary: The author explains the maximum operating power of each chip, the temperature of surrounding, and the emissivity of the chip.
Chips of width
L
=
15
mm
on a side are mounted to asubstrate that is installed in an enclosure whose wallsand air are maintained at a temperature of
T
s
u
t
=
25
°
C
.The chips have an emissivity of
∈
=
0.60
and a maximum allowable temperature of
T
s
=
85
°
C
.
(a) If heat is rejected from the chips by radiation andnatural convection, what is the maximum operatingpower of each chip? The convection coefficientdepends on the chip-to-air temperature differenceand may be approximated as
h
=
C
(
T
s
−
T
∞
)
1
/
4
, where
C
=
4.2
W
/
m
2
⋅
K
5
/
4
. (b) If a fan is used to maintain airflow through theenclosure and heat transfer is by forced convection, with
h
=
250
W
/
m
2
⋅
K
, what is the maximum operating power?
Chips of width L _ 15 mm on a side are mounted to a substrate that is installed in an enclosurewhose walls and air are maintained at a temperature of Tsur=T∞=25oC. The chips have an emissivity ofε=0.60 and a maximum allowable temperature of Ts=85oC.(a) If heat is rejected from the chips by radiation and natural convection, what is the maximum operatingpower of each chip? The convection coefficient may be approximated as h=11.7 W/m2K.(b) If a fan is used to maintain airflow through the enclosure and heat transfer is by only forcedconvection, with h=250 W/m2K, what is the maximum operating power?
A geodesic dome constructed with an aluminum frameworkis a nearly perfect hemisphere; its diameter measures 55.0 m on a winterday at a temperature of -15°C. How much more interior space does thedome have in the summer, when the temperature is 35°C?
Chips of width L _ 15 mm on a side are mounted to a substrate that is installed in an enclosure
whose walls and air are maintained at a temperature of Tsur=T∞=25oC. The chips have an emissivity of
ε=0.60 and a maximum allowable temperature of Ts=85oC.
(a) If heat is rejected from the chips by radiation and natural convection, what is the maximum operating
power of each chip? The convection coefficient may be approximated as h=11.7 W/m2K.
(b) If a fan is used to maintain airflow through the enclosure and heat transfer is by only forced
convection, with h=250 W/m2K, what is the maximum operating power
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, mechanical-engineering and related others by exploring similar questions and additional content below.