PROBLEM 1.2
KNOWN: Thickness and thermal conductivity of a wall. Heat flux applied to one face and
temperatures of both surfaces.
FIND: Whether steady-state conditions exist.
SCHEMATIC:
L = 10 mm
T2 = 30C
q = 20 W/m2
T1 = 50C
qcond
k = 12 W/mK
ASSUMPTIONS

NAME_
MEM 345
Drexel University
Summer 2009-10
Mechanical Engineering and Mechanics
Midterm Examination 1
(Open book and closed notes)
Note: Per university regulations, all forms of academic dishonesty will be addressed in a strict
manner. The student may

NAME_
MEM 345
Drexel University
Summer 2009-10
Mechanical Engineering and Mechanics
Midterm Examination 1
(Open book and closed notes)
Note: Per university regulations, all forms of academic dishonesty will be addressed in a strict
manner. The student may

NAME_
Drexel University
Mechanical Engineering and Mechanics
MEM 345
Heat Transfer (Spring 2010)
Final Exam
(Open book and closed notes)
Note: Per university regulations, all forms of academic dishonesty will be addressed in a
strict manner. The student m

Chapter 2 Introduction to Conduction
The conduction rate equation Considering one-dimensional heat transfer
dT qx kx A dx qx dT " qx kx A dx
Heat flux is a directional quantity
"A" is area normal to the heat flow direction.
Alternative form of the

Chapter 2
Introduction to Conduction
The conduction rate equation
Considering one-dimensional heat transfer
dT
qx = k x A
dx
qx
dT
"
qx =
= k x
A
dx
Heat flux is a directional quantity
A is area normal to the heat flow direction.
Alternative form of the F

CHAPTER THREE
STEADY-STATE ONE DIMENSIONAL HEAT
CONDUCTION
Methodology
Specify appropriate form of the heat equation.
Solve for the temperature distribution
Apply Fouriers law to determine the heat flux.
Simplest Case: One-Dimensional, Steady-State
Con

MEM 345
HEAT TRANSFER
Heat: A form of energy that appears only in transit
(recall work and heat interactions in your study of
thermodynamics)
What is meant by heat transfer?
Heat Transfer is thermal energy in transit due to temperature difference
For eng

One-Dimensional, Steady-State
Conduction without
Thermal Energy Generation
Chapter Three
Space Shuttle heat tiles
3.1 Plane Wall
Why do we want to find temperature profile?
T1 = 100oC
Objective: to fine T(x)
Solution
1. T(x) = ax + b
2. x = 0; T = T1
3. x

PROBLEM 1.4
KNOWN: Dimensions, thermal conductivity and surface temperatures of a concrete slab. Efficiency
of gas furnace and cost of natural gas.
FIND: Daily cost of heat loss.
SCHEMATIC:
ASSUMPTIONS: (1) Steady state, (2) One-dimensional conduction, (3

PROBLEM 2.3
KNOWN: Hot water pipe covered with thick layer of insulation.
FIND: Sketch temperature distribution and give brief explanation to justify shape.
SCHEMATIC:
ASSUMPTIONS: (1) Steady-state conditions, (2) One-dimensional (radial) conduction, (3)

PROBLEM 3.3
KNOWN: Temperatures and convection coefficients associated with air at the inner and outer surfaces
of a rear window.
FIND: (a) Inner and outer window surface temperatures, Ts,i and Ts,o, and (b) Ts,i and Ts,o as a function of
the outside air

External Flow:
The Flat Plate in Parallel Flow
Chapter 7
Section 7.1 through 7.3
Physical Features
Physical Features
As with all external flows, the boundary layers develop freely without constraint.
Boundary layer conditions may be entirely laminar, la

CHAPTER THREE
STEADY-STATE ONE DIMENSIONAL HEAT CONDUCTION
Methodology
Specify appropriate form of the heat equation.
Solve for the temperature distribution.
Apply Fouriers law to determine the heat flux.
Simplest Case: One-Dimensional, Steady-State Co

Internal Flow:
Heat Transfer Correlations
Chapter 8
Sections 8.4 through 8.6
Fully Developed Flow
Fully Developed Flow
Laminar Flow in a Circular Tube:
The local Nusselt number is a constant throughout the fully developed
region, but its value depends on