Lecture 5 Extended Surfaces, a.k.a. Fins
In convection cooling applications, we often are faced with the fact that the heat transfer
coefficients are too limited to remove heat efficiently from a surf
Lecture 2 Conduction Heat Transfer
More on Fouriers Law
In the last lecture we have touched on Fouriers law of conduction where the heat flux vector is
given by:
T
T T
q kT k i
j
y
z
x
k
(2.1)
whe
Lecture 1
Overview
So what exactly is Transport Phenomena? The answer is simple, it is the mechanism by which
we move certain things from one place to another. What are those certain things then? As
m
Lecture 6 Transient Conduction
Most of what we have discussed in this class up to this point did not account for time variation.
In some cases, we are actually interested in how temperatures and heat
Lecture 8 Mass Diffusion Boundary Conditions
Even though the mass diffusion equation are essentially identical to the conduction equation, and
conduction solutions can often be used to obtain mass tra
Lecture 11 Convection Correlation
Using Correlations
Since this is only an introductory class, I will only hold you responsible for simple geometries,
namely flow over flat plates, cross-flow over lon
Lecture 7 Mass Diffusion
Introduction
We have learned so far that heat is conducted (diffused) from high temperature to low
temperature. Likewise, a mass species in a mixture will also diffuse from re
Lectures 12 & 13 Internal Flow Convection
Background
So far we have considered external flow convection such as flow over a flat plate, a cylinder or a
sphere. Internal flow is characterized by the fa
Lecture 4 Conduction Heat Transfer, continued
More on Thermal Resistances
In the last lecture we ended the discussion with the thermal resistances for all three geometries,
namely plane slab, cylindri
Lecture 3 Conduction Heat Transfer, continued
One-Dimensional Conduction Equation
In the last lecture we have obtained the generic heat conduction equation for one-dimensional
slabs, which is repeated
MAE 105D, Transport Phenomena
Transient Heat Transfer Experiment
DUE DATE: Thursday, March 3
You may work individually or in pairs.
This is intended to be an open-ended experimental investigation in w
PROBLEM 9.14
KNOWN: Aluminum plate (alloy 2024) at an initial uniform temperature of 227 C is suspended in a
room where the ambient air and surroundings are at 27 C.
FIND: (a) Expression for time rate
PROBLEM 6.77
KNOWN: Water freezing under conditions for which the air temperature exceeds 0 C.
FIND: (a) Lowest air temperature, T , before freezing occurs, neglecting evaporation, (b)
The mass transf
PROBLEM 8.9
KNOWN: Flow rate and properties of oil flowing in pipe. Dimensions of pipe.
FIND: Pressure drop, flow work, temperature rise caused by flow work.
SCHEMATIC:
L = 100 km
Oil
.
m = 500 kg/s
PROBLEM 9.77
KNOWN: Sphere with embedded electrical heater is maintained at a uniform surface temperature
when suspended in various media.
FIND: Required electrical power for these media: (a) atmosphe
Solution to my own questions on homework # 2
1. 10 people on each side of the room, left side $5 each, right side $3 each
a. Exchange 5 people from one side to the other and split the money equally. E
Homework # 2
Due in class Thu Jan 21
I know this is a lot of homework for one week, but bear with me this time since I got the book
rather late in the quarter. Better to sweat during homework time tha
Homework # 5
Due in class Thursday February 18, 2016
Textbook problems:
6.3
Note that u is given so you dont have to look for
6.7
Leading edge is at x 0 while trailing edge is at x L
6.14
Stagnation
105D Experiments
The objective of this experiment is to measure the convective coefficient for each air flow
velocity. So you set the air flow velocity from the PWM controller, and you can get the vel
Lectures 9 & 10 Convection Heat and Mass Transfer
So far we have considered diffusion in stationary media such as conduction through slabs,
cylinders, etc. In all these problems, there is no bulk moti
Lecture 14 Natural Convection, a.k.a. Free Convection
Background
Natural convection occurs when there is a temperature difference between a surface and the
surrounding quiescent fluid. If the plate is
Lecture 16 Radiation Heat Transfer
Background
All materials emit radiation via electromagnetic waves, basically the same as light. This is
caused by the transitions in energy levels of the electrons t
for an opaque surface
Then the radiation heat flux can be expressed as the difference between outgoing and
incoming energy,
q"_rad = J - G = E + rho*G - G = E - alpha*G (for tau = 0)
Students Name:
Transport Phenomena 105D
Instructor: Dr. Mohammad Janbozorgi
UCLA Fall 2017
1. a) Give the expression for the Bio number, b) What is the Physical interpretation of the Bio
number? C) Dr
Discussion Week 7
PROBLEM 6.14
KNOWN: Radial distribution of local convection coefficient for flow normal to a circular
disk.
FIND: Expression for average Nusselt number.
SCHEMATIC:
ASSUMPTIONS: Const
Transport Phenomena 105D
Practice Problems
Problem 1: A square isothermal chip is of width w = 5 mm on a side and is mounted in a substrate
such that its side and back surfaces are well insulated; the