ME421Heat
Transfer
Chapter 6
Introduction to Convection
Velocity Boundary Layer
Thermal Boundary Layer
Heat transfer between the surface and fluid.
A region of the flow characterized by temperature gradients and heat fluxes
A region between the surface an

ME 421
Heat Transfer
Chapter 8
Internal Flow
An inviscid flow is the flow of an ideal fluid that is assumed to have no viscosity
Velocity profile is parabolic for laminar flow
The Reynolds number for flow in a circular tube is defined as
where um is the m

Heat Transfer:
Physical Origins
and
Rate Equations
Chapter One
Sections 1.1 and 1.2
Heat Transfer and Thermal Energy
What is heat transfer?
Heat transfer is thermal energy in transit due to a temperature
difference.
What is thermal energy?
Thermal energ

ME 421
Heat Transfer
The Hyperbolic Functions
x
Energy balance on element (x Ac)
Boundary conditions:
Solution
Solution
Example 3.9
Fin Effectiveness f
Fin Efficiency f
Assignment 4
Due date February 23, 2016
Assignment 4
Due date February 23, 2016
Assign

ME 421
Introduction to Radiation
Chapters 12 and 13
Plan angle, (radian)
Solid Angle, (steradian)
Solid Angle, (steradian)
isthezenith angle, radian
is the azimuth angle, radian
Radiation Intensity and Its Relation to Emission
We define I,e as the rate

ME 421
Introduction to Radiation
Chapter 12
C
v
wavelength (m)
speed of light (m/s)
frequency (Hz)
As the frequency v increases the wavelength decreases
PHOTON RADIATION
The energy of the photon, E, is given by
where h is Plancks constant (6.6256 1034 J s

Fouriers Law
and the
Heat Equation
Chapter Two
Fouriers Law
Fouriers Law
A rate equation that allows determination of the conduction heat flux
from knowledge of the temperature distribution in a medium
Its most general (vector) form for multidimensional

One-Dimensional, Steady-State
Conduction without
Thermal Energy Generation
Chapter Three
Sections 3.1 through 3.4
Methodology
Methodology of a Conduction Analysis
Specify appropriate form of the heat equation.
Solve for the temperature distribution.
Apply

ME421
Heat Transfer
Chapter 7
External Flow
Our primary objective is to determine convection coefficients
for different flow geometries
The local and average convection coefficients may be
correlated by equations of the form
Our primary objective is to de

ME421
Heat Transfer
Chapter 9
Free Convection
In free convection fluid motion is due to buoyancy
forces within the fluid, while in forced convection it
is externally imposed.
The density of gases and liquids depends on
temperature, generally decreasing (d

ME 421
Heat Transfer
Chapter 5
Transient Conduction
The Lumped Capacitance Method
Resistance to convection heat transfer
Lumped thermal capacitance of the solid
Validity of the Lumped Capacitance Method
the Biot number
If the following condition is satisf