PROBLEM 1.16
KNOWN: Dimensions and thermal conductivity of a chip. Power dissipated on one surface.
FIND: Temperature drop across the chip.
SCHEMATIC:
ASSUMPTIONS: (1) Steady-state conditions, (2) Constant properties, (3) Uniform heat
dissipation, (4) Neg

PROBLEM 3.133
KNOWN: Thickness, length, thermal conductivity, and base temperature of a rectangular fin. Fluid
temperature and convection coefficient.
FIND: (a) Heat rate per unit width, efficiency, effectiveness, thermal resistance, and tip temperature
f

PROBLEM 3.76
KNOWN: Spherical tank of 3-m diameter containing LP gas at -60C with 250 mm thickness of
insulation having thermal conductivity of 0.06 W/mK. Ambient air temperature and convection
2
coefficient on the outer surface are 20C and 6 W/m K, respe

24-322 Heat Transfer, Fall 2014 HW#3
Assigned: Sept 11, 2014
Due: September 18, 2014 (at the beginning of class)
A. In this problem you will derive the temperature distribution in a cylindrical solid with
!
outer radius ro and heat generation q . The gove

PROBLEM 3.114
KNOWN: Wire diameters associated with a thermocouple junction, value of the convection heat
transfer coefficient.
FIND: Minimum wire lengths necessary to ensure the junction temperature is at the gas temperature.
SCHEMATIC:
Thermocouple junc

PROBLEM 7.69
KNOWN: Dimensions and thermal conductivity of a thermocouple well. Temperatures at well tip
and base. Air velocity.
FIND: Air temperature.
SCHEMATIC:
ASSUMPTIONS: (1) Steady-state conditions, (2) Constant properties, (3) One-dimensional
condu

PROBLEM 6.32
KNOWN: Local Nusselt number correlation for flow over a roughened surface.
FIND: Ratio of average heat transfer coefficient to local coefficient.
SCHEMATIC:
ANALYSIS: The local convection coefficient is obtained from the prescribed correlatio

24-322 Heat Transfer, Fall 2016 HW#5
Assigned: October 13, 2016
Due: October 20, 2016 (at the beginning of class)
Textbook problems 7.69, 7.83, 8.6, and 8.12
Numerical Answers
7.69: T_inf = 452.2 K
7.83: L = 0.18 m
8.6:
a)
Liquid
um [m/s]
Water
0.033
Engi

PROBLEM 8.31
KNOWN: Thermal conductivity and inner and outer diameters of plastic pipe. Volumetric flow rate and inlet
and outlet temperatures of air flow through pipe. Convection coefficient and temperature of water.
FIND: Pipe length and fan power requi

24-322 Heat Transfer, Fall 2016 HW#3
Assigned: Sept 15, 2016
Due: September 22, 2016 (at the beginning of class)
A. In this problem you will derive the temperature distribution in a cylindrical solid with
outer radius ro and heat generation q! . The gover

24-322 Heat Transfer, Fall 2016 HW#6
Assigned: October 20, 2016
Due: October 27, 2016 (at the beginning of class)
8.31: L = 13.7 m, P = 0.077 W
8.55: (a) n/a; (b) Tm,o = 17.7 C, Ts,o = 66.5 C
8.82: (a) n/a; (b) Tm,o = 305.3 K, q = 15700 W
11.1: U = 222 W/

24-322 Heat Transfer, Fall 2016 HW#4
Assigned: October 6, 2016
Due: October 13, 2016 (at the beginning of class)
A. Lumped Capacitance Demonstration
a. Using the raw data posted on Blackboard, plot the temperature history and fitted curve on
the same figu

!
!
!
!
PROBLEM 3.50
KNOWN: Wall thickness and diameter of stainless steel tube. Inner and outer fluid temperatures
and convection coefficients.
FIND: (a) Heat gain per unit length of tube, (b) Effect of adding a 10 mm thick layer of insulation to
outer s

24-322 Heat Transfer, Fall 2016 HW#1
Assigned: Sept 1, 2016
Due: September 8, 2016 (at the beginning of class)
A. Pick one of the following household items: barbecue (gas or charcoal), electrical space
heater, hot water heater. In less than one typed page

24-322 Heat Transfer, Fall 2016 HW#2
Assigned: Sept 8, 2016
Due: September 15, 2016 (at the beginning of class)
A. The Open-ended Question:
Youre spending the summer in Pittsburgh. If the indoor temperature Tin of your
apartment is to be kept constant, ho

PROBLEM 3.137
KNOWN: Dimensions and end temperatures of pin fins.
FIND: (a) Heat transfer by convection from a single fin and (b) Total heat transfer from a 1
2
m surface with fins mounted on 4mm centers.
SCHEMATIC:
ASSUMPTIONS: (1) Steady-state, (2) One-