Problem 19.7 (WWWR)

)3

)

3/4 3/20

19.7 (a)

}

3/4 3/20

19.7(b)

1)

19.7 Part C

Nusselt No.

.

1/3

3/ 4

( )3(0)

2

( )3 Pr

21

( )

s

t

s

s

T Tq dTk k

A dy

T Tk

X

x

h T T

Dear CN2125 Students:

Attached please find the summary of the relevant sections for the module CN2125. As

mentioned in the lecture, I have used WWWR as the MAIN TEXTBOOK (mandatory).

The ID is used as the REFERENCE (optional, you may refer these sections in the library

if needed) to clarify weak/unclear sections from WWWR. It is recommended that you do

not go through the over 300 pages of text in the respective books randomly. Instead,

please follow my highlighted sections below for your study on the subject - Your best

strategy for scoring high with comfortable study and ease for the module.

Week #1 Covered Sections in WWWR/ID

WWWR Chapter 15 (whole chapter, except pg. 203 for detailed derivation of thermo-

conductivity from gas kinetic theory)

WWWR Chapter 16 (whole chapter, except pg. 219-220 on detailed derivations for

Equations 16-6 to 16-13)

ID Chapter 1 (sections 1.1-1.2.3: p.2-p.9)

ID Chapter 2 (section 2.3 p.70-74 & p.77-79)

Week #2 Covered Sections in WWWR/ID

WWWR Chapter 17 (whole chapter except p.240-246).

Two questions from ID were used to highlight the problems of steady heat conduction.

Week #3 Covered Sections in WWWR/ID

WWWR Chapter 18 (whole chapter except p.263-270)

ID Chapter 5: Semi-infinite conduction: detailed derivation for the transformation of

variables: section 5.7 (p.284-285)

Two extra questions from ID were used to highlight the problems of unsteady heat

conduction.

Week #4 Covered Sections in WWWR/ID

WWWR Chapter 19 (whole chapter except the section on turbulent flow considerations p.

301-305).

**Note: Sections 19.4 & 19.5 involve complicated mathematical derivations. You should

just understand the physical meanings of these derivations. These concepts will help you

to understand (theoretically how the heat transfer coefficient can be correlated). The

detailed mathematical derivations in these two sections are for your references only and

will not show up in quizzes and examination.

Five extra questions from ID were used to highlight the boundary layer problems.

Week #5 Covered Sections in WWWR/ID

WWWR Chapter 20 (whole chapter except p.316-318).

Two extra questions from ID were used to highlight the problems of convective heat-

transfer correlations.

Week #6 Covered Sections in WWWR/ID

WWWR Chapter 21 (whole chapter)

One extra question from ID was used to highlight the problem of condensation heat-

transfer problem.

WWWR Chapter 22 (Sections 22.1, 22.2 & 22.3)

Only the basic concepts of heat exchangers (pages 336-347) are covered. The other more

advanced topics for heat exchangers although not covered in lectures are reserved for

self-studies.

Week #7 Covered Sections in WWWR/ID

WWWR Chapter 24 (whole chapter).

One extra question from ID (#14.23) was used to illustrate the mass transfer resistance

for diffusion in composite.

Week #8 Covered Sections in WWWR/ID

WWWR Chapter 25 (whole chapter except some detailed mathematical derivations).

Reviews for various topics covered in earlier lectures.

Sincerely yours,

Dr. Chi-Hwa Wang, Instructor, CN2125