k k k
SOLUTIONS MANUAL
k
,TABLE OF CONTENTS
k k
Chapter 1 Introduction
k k
Chapter 2 Pressure Distribution in a Fluid Chapter
k k k k k k k
3 Integral Relations for a Control Volume Chapter
k k k k k k k k k
4 Differential Relations for Fluid Flow Chapter 5 D
k k k k k k k k
imensional Analysis and Similarity Chapter 6 Visc
k k k k k k
ous Flow in Ducts
k k k
Chapter 7 Flow Past Immersed Bodies
k k k k k
Chapter 8 Potential Flow and Computational Fluid Dynamics C
k k k k k k k k
hapter 9 Compressible Flow
k k k
Chapter 10 Open-k k
Channel Flow Chapter 11 Turbomachi
k k k k
nery
APPENDIX F k
, Chapterk1k •k Introductio 1-1
n
Chapter 1 • Introduction
k k k
P1.1
Akgaskatk20Ckmaykbekrarefiedkifkitkcontainsklesskthank1012kmoleculeskperkmm3.kI
fkAvogadro’sknumberkisk6.023E23kmoleculeskperkmole,kwhatkairkpressurekdoeskthiskrepresen
t?
Solution: Thekmasskofkonekmoleculekofkairkmaykbekcomputedkas
Molecularkweight 28.97kmol−1
mk= =
=k4.81E−23kgkAvogadro’sknumber
6.023E23kmolecules/gmol
Thenkthekdensitykofkairkcontainingk1012kmoleculeskperkmm3kis,kinkSIkunits,
k=k 1012 moleculeskk4.81E−23
moleculek
g
3
mm
gk =k4.81E−5k kg
=k4.81E−11
mm3 m3
Finally,kfromkthekperfectkgasklaw,kEq.k(1.13),katk20Ck=k293kK,kwekobtainkthekpressure:
kgk 2k k
pk=kkRTk=kk4.81E−5k 3k k287k m2 (293kK)k=k4.0kP ns.
a m s Kk
Copyrightk©kMcGraw-
HillkEducation.kAllkrightskreserved.kNokreproductionkorkdistributionkwithoutkthekpriorkwrittenkconsentkof
McGraw-HillkEducation.
, Chapterk1k •k Introductio 1-2
n
P1.2k TablekA.6klistskthekdensitykofkthekstandardkatmospherekaskakfunctionkofkaltitude.k Us
ekthesekvaluesktokestimate,kcrudely,ksay,kwithinkakfactorkofk2,ktheknumberkofkmoleculeskofkai
rkinkthekentirekatmospherekofkthekearth.
Solution:k k Makekakplotkofkdensitykkversuskaltitudekzkinkthekatmosphere,kfromkTablekA.6:
1.2255kkg/m3
DensitykinkthekAtmosphere
0 z 30,000km
Thiskwriter’skapproximation:k Thekcurvekiskapproximatelykankexponential,kkkok exp(-
bz),kwithkbkapproximatelykequalktok0.00011kperkmeter.k Integratekthiskoverkthekentirekatmospher
e,kwithkthekradiuskofkthekearthkequalktok6377kkm:
m =
kdk(vol)k 2[k e−bkzk](4kR dz)k =
atmosphere 0 o earth
ok4kRearth
2
(1.2255kkgk/km3k)4k(6.377E6km)
= =
2
k k 5.7E18k kg
b
0.00011k/km
Dividingkbykthekmasskofkonekmoleculekk4.8E−23kgk(seekProb.k1.1kabove),kwekobtain
kthektotalknumberkofkmoleculeskinkthekearth’skatmosphere:
N molecules =k
m(atmosphere)k
=
5.7E21kgrams k 1.2Ε44 molecules Ans.
m(onekmolecule) 4.8E−23kgm/molecule
Thiskestimate,kthoughkcrude,kiskwithink10kperkcentkofkthekexactkmasskofkthekatmosphere.
Copyrightk©kMcGraw-
HillkEducation.kAllkrightskreserved.kNokreproductionkorkdistributionkwithoutkthekpriorkwrittenkconsentkof
McGraw-HillkEducation.