Heat transfer I
Dr.Moosavi
Homework set 4
Due date: 91/1/27
1) Consider steady one-dimensional heat conduction in a plane wall with variable heat generation and variable
thermal conductivity. The nodal network of the medium consists of nodes 0, 1, and 2 w
1
9
1- A diffuse material at 2000K has the following spectral, directional emissivity diagram. Determine
the total hemispherical emissivity at this temperature. Determine the emissive power over the
spectral range 0.8 to 2.5 m and for the directions
10
0
:
0- . .
) 0001
) 2 3 .
3/1=13 , F 12 F .
2-
0)3(1-(2/3)(L2/L
2)22/Pi(1-(1/3)(L1/L
3)2(1-(1/3)(L1/L
4)1Pi/2(1-(2/3)(L2/L
3- A diffuse and gray heat source has the dimensions 5m X 5m. Its power input is 75 kW. A panel with
the same dimension
1
- :3
1. . 6
. 5 W/m.k .
:
Temperature profile= Ax^2+ Bx+C
X=0T=130 C
Temperature of the air= 20 C
The wall is well insulated at x=60mm
2^h=500 W/m
) .
)
2. 1 mm 440 .
Heat transfer 1
Due time:1390/12/23
1) Consider a 1.2-m-high and 2-m-wide double-pane window consisting of two 3-mm-thick
layers of glass (k = 0.78 W/m C) separated by a 12-mm-wide stagnant air space
(k =0.026 W/m C). Determine the steady rate of heat tra
Heat Transfer 1 - Due date: 7 khordad
7
Course by Dr.moosavi TA: Amir Darabi
1) A small surface of area A1=4 cm2 emits radiation as a blackbody at T1= 800 K. Part of the radiation
emitted by A1 strikes another small surface of area A2= 4 cm2 oriented as
Heat transfer I Course by Dr. A.Moosavi
Homework set 5
Due Time: midterm exam
1) A 0.3-cm-thick, 12-cm-high, and 18-cm-long circuit board houses 80 closely spaced
logic chips on one side, each dissipating 0.04 W. The board is impregnated with copper
filli
1
:
_
.1 . 6
. 5 W/m.k .
:
Temperature profile= Ax^2+ Bx+C
X=0 T=130 C
Temperature of the air= 20 C
The wall is well insulated at x=60mm
2^h=500 W/m
( .
(
.2 1 m
Heat transfer I
*HAPPY
Homework set 3 Due date: 91/1/15
NOROUZ*
1) The boiling temperature of nitrogen at atmospheric pressure at sea level (1 atm pressure) is -196C.
Therefore, nitrogen is commonly used in low-temperature scientific studies since the tem
Heat Transfer 1 -Due date:31/2/1391 Course by Dr.Moosavi TA: Amir Darabi
1.A test is conducted to determine the overall heat transfer coefficient in a
shell-and-tube oil-towater heat exchanger that has 24 tubes of internal diameter 1.2
cm and length 2 m i
Heat Transfer 1 - Due date: 07 exam
Final
Course by Dr :moosavi
TA: Amir Darabi
1) Consider a conical enclosure of height h and base diameter D. Determine the view factor from
the conical side surface to a hole of diameter d located at the center of the b