Engineering Thermodynamics and Fluid Mechanics Fifth Edition WBUT–2016 [5 ed.]

Table of contents :
Title
1 Thermodynamic Concept sand the Zeroth Law
2 Heat and Work
3 First Law of Thermodynamics
First 4 Law Applied to Flow Processes
5 Second Law of Thermodynamics
6 Entropy
7 Properties of Pure Substances
8 Properties of Gas
9 Air-Standard Cycles
10 Power Cycles
11 Properties of Fluids
12 Fluid Statics
13 Kinematics of Fluid Flow
14 Dynamics of Ideal Fluids
Appendix I
Appendix II
Appendix III
Question Papers
REFERENCES

Citation preview

Engineering Thermodynamics and Fluid Mechanics Fifth Edition WBUT–2016

ABOUT THE AUTHORS P K Nag had been with the Indian Institute of Technology Kharagpur, for about four decades, almost since his graduation. After retirement from IIT, he was an Emeritus Fellow of AICTE, New Delhi, stationed at Jadavpur University, Kolkata, till June 2005. He was a Visiting Professor in the Technical University of Nova Scotia (now Dalhousie University), Halifax, Canada, for two years during 1985–86 and 1993–94. Dr Nag has been a recipient of the President of India medal (1995) from the Institution of Engineers (India). He was a Fellow of the National Academy of Engineers (FNAE) and a Fellow of the Institution of Engineers ! " # Member of the Indian Society for Technical Education, Indian Society for Heat and Mass Transfer, and the Combustion Institute, USA (Indian section). He was also a member of the New York Academy of Sciences, USA. $ % & ' ' *' law analysis of thermal systems, and waste heat recovery. He authored four books and more than 150 research papers in several national and international journals and proceedings. He had attended several +- / ! 7 Sukumar Pati is currently working as Assistant Professor in the Department of Mechanical Engineering at National Institute of Technology, Silchar. Prior to joining NIT Silchar, he worked as a Post-doctoral Fellow for almost one year at Indian Institute of Technology Kharagpur after completion of his PhD from ; < " * * $ 7 !< ; < */ = 7 * < + 7 ! - 7 ; > $ ' ;< ? ; *! < < - ' @ ! Dr Pati joined Haldia Institute of Technology, Haldia, in the Department of Mechanical Engineering in 2001 and served till 2007 at various positions. He is author of the textbook, A Textbook on Fluid Mechanics and Hydraulic Machines and co-author of the textbook Engineering Mechanics (WBUT) both published by McGraw Hill Education (India). He has published several research papers in international journals of repute. $ 7 7 * L % % 7 L % * T K Jana is currently working as Professor and Head, Department of Mechanical Engineering at Haldia $ $ 7 !< ; < *! < College, Shibpur, Howrah (presently Indian Institute of Engineering Science and Technology, Shibpur, West ! ;O < O " */ 7 + 7 > $ Q $ " * ; < RXXR ! " / 7 several portfolios. He is a member of Institute of Engineers and is the co-author of the textbook Engineering Mechanics (WBUT) published by McGraw Hill Education (India). Dr Jana has published several papers in national and international journals, and conferences. His areas of interest include CNC machining, Holonic manufacturing systems, and agent-based systems.

Engineering Thermodynamics and Fluid Mechanics Fifth Edition WBUT–2016 P K Nag Former Professor Indian Institute of Technology Kharagpur, West Bengal

Sukumar Pati Assistant Professor National Institute of Technology, Silchar Assam

T K Jana Professor and Head Department of Mechanical Engineering Haldia Institute of Technology Haldia, West Bengal

McGraw Hill Education (India) Private Limited NEW DELHI McGraw Hill Education Offices New Delhi New York St Louis San Francisco Auckland Bogotá Caracas Kuala Lumpur Lisbon London Madrid Mexico City Milan Montreal San Juan Santiago Singapore Sydney Tokyo Toronto

McGraw Hill Education (India) Private Limited O ' ' ; = $ < O 7 P-24, Green Park Extension, New Delhi 110 016

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Engineering Thermodynamics and Fluid Mechanics, 5/e (WBUT-2016) Z RX[\ RX[] RX[^ RX[_ RX[R ' ; =

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` O * 2.17 Other Modes of Work 2.17 Some Exceptional Cases 2.19 Summary 2.20 Review Questions 2.21 Numerical Problems 2.21 Multiple-Choice Questions 2.22

3. First Law of Thermodynamics 3.1 _R __ _^ _] _\

Joule’s Experiment 3.1 ? # * * ? # $ ` O $ < ? # * *

3.2 * < "

3.1-3.24

*

* 3.6 3.8 3.9 O 3.12

Summary 3.21 Review Questions 3.21 Numerical Problems 3.22 Multiple-Choice Questions 3.23

4. First Law Applied to Flow Processes 4.1 4.2 ^_ 4.4

Control Volume 4.1 Steady Flow Processes and Devices 4.1 ; ! < ! Applications of Energy Equation 4.5

4.1-4.18

?

4.1

O

Summary 4.15 Review Questions 4.16 Numerical Problems 4.17 Multiple-Choice Questions 4.18

5. Second Law of Thermodynamics 5.1 5.2 5.3 5.4 ]] ]\ 5.7

Introduction 5.1 Thermal Energy Reservoir 5.1 Heat Engines 5.2 Refrigerators and Heat Pumps 5.3 7 ‰O >- * # 5.6 - * # 5.7 Equivalence of Kelvin–Planck and Clausius Statements

5.1-5.40

5.7

ix

Contents

5.8 5.9 ] [X 5.11 ] [R

Reversible and Irreversible Processes 5.9 The Carnot Cycle 5.9 # * * Carnot Heat Engine, Refrigerator and Heat Pump < 5.33

5.11 5.17

Summary 5.35 Review Questions 5.37 Numerical Problems 5.38 Multiple-Choice Questions 5.39

6. Entropy 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8

6.1-6.21

Two Reversible Adiabatic Paths cannot Intersect Each Other Clausius Inequality 6.1 Entropy—A Property of a System 6.3 Temperature Entropy Diagram 6.7 Entropy Principle and Applications 6.10 Entropy Generation in a Closed System 6.13 Entropy and Disorder 6.14 Thermodynamic Property Relations 6.15

6.1

Summary 6.18 Review Questions 6.18 Numerical Problems 6.19 Multiple-Choice Questions 6.20

7. Properties of Pure Substances 7.1 7.2 7.3 7.4 7.5

Introduction 7.1 Property Diagrams 7.1 P-V-T Surface 7.6 Quality or Dryness Fraction Steam Tables 7.7

7.1-7.16

7.6

Summary 7.14 Review Questions 7.15 Numerical Problems 7.16 Multiple-Choice Questions 7.16

8. Properties of Gas 8.1 8.2 {_

Equation of State of a Gas Ideal Gas 8.1 $
? > / @ B , & ' Answer: & '

u = cos q is:

9

5

Group-B (Short-Answer Questions) (Answer any three questions) E 8

/ *G

$B H $B

4 '

3 ¥ 5 = 15 E#

* E **

3

E#

/

$

+ * / E # ' * / ' (ii) The process follows the path, pvn = constant, where n L HE!E 8 $ / E Answer: The problem is worked out in Example 2.5.

/ 9

-

6 '

3E

M

B

N

SQP 2015.3

HG

B '

* + / E Answer: Refer to Section 12.3. # ' ' u = 0.5y – y2 in which u ' O y ' E, y L EH * ' * is 5 Poise. Answer: The problem is identical to the one worked out in Example 11.2. !E 6 5 Q *' E Answer: Refer to Section 11.7. ? ** * ' * + * / @ -> E Answer: Refer to Section 11.7.2. GE # * H HG ' E / / * ' * / / H R O E, the velocity at section 2. Answer: The problem is identical to the one worked out in Example 13.7. SE , ' * * * / * E? ' / * / ' * * / @ Answer: Refer to Sections 5.4.1 and 5.4.2.

Group-C (Long-Answer Questions) (Answer any three questions) UE ? $ * Answer: Refer to Section 11.10. # / ' EU 54 O 2E ? * HG O *S E2 / ' * > + Answer: W' Area of the plate: X * + Velocity of plate: Let F1

F2

3 ¥ HG L !G

@ G

9 G

G *

+

* '

'

/

*' E

AL G ¥ G m L EU 5Y O 2 V L EHG O *

LS G

2

* *

L E S G

2

* *

* S

' /E HE

E

SQP 2015.4

- /

/#

"

Fig. 1 5

Q

*'

*

t1 = m where, dy L

t 1 = 0.7 ¥

6

*

*

t1 is given by:

du dy L S ¥ 10 –3

LS

or

*

0.15 = 17.5 N/m 2 6 ¥ 10-3

* F1 = shear stress ¥ area = t1 A = 17.5 ¥ E S G L HE _! 5

5

Q

*'

*

t2 = m where, dy L

t 2 = 0.7 ¥ *

*

t2 is given by:

du dy L G Y S L H_

or 6

*

L H_ ¥ 10–3

0.15 = 5.526 N/m 2 19 ¥ 10-3

* F2 = shear stress ¥ area = t2 A = 5.526 ¥ E S G L E3!G 5

> *

+ >

*

*

+

F = F1 + F2 L HE _! j E3!G L HE!3_ 5 ? @ Answer: Refer to Section 7.1.

*

E#

*

6 '

M

B

N

SQP 2015.5

HG

RE , ' > * + * Answer: Refer to Section 13.5.2. � � � � # /' v = x 2 yi + y 2 zj - (2 xyz + yz 2 )k E 6 E8 ' Answer: # ' ' * # + ** * *

E * H 3E E

∂u ∂v ∂w + + =0 ∂x ∂y ∂z u = x2y, v = y2z, w = – (2xyz + yz2) Therefore,

∂u ∂v ∂w = 2 xy , = - ( 2 xy + 2 yz ) = 2 yz , ∂x ∂z ∂y ∂u ∂v ∂w + + =0 ∂x ∂y ∂z

# * Velocity vector is given as:

E

� V = x 2 yiˆ + y 2 zjˆ - (2 xyz + yz 2 )kˆ Therefore, velocity at (2, 1, 3) is:

� V

( 2,1, 3)

= ÈÎ22 ¥ 1˘˚ i� + ÈÎ12 ¥ 3˘˚ j� - ÈÎ2 ¥ 2 ¥ 1 ¥ 3 + 1 ¥ 32 ˘˚ k� = 4i� + 3 j� - 21k� a x, a y

#

Given that: Hence,

az are given by:

ax =

∂u ∂u ∂u ∂u +u +v +w ∂t ∂x ∂y ∂z

ay =

∂v ∂v ∂v ∂v +u +v +w ∂z ∂y ∂x ∂t

az =

∂w ∂w ∂w ∂w +u +v +w ∂t ∂x ∂y ∂z

u = x 2y

∂u ∂u ∂u ∂u = 2 xy , = x2, =0 = 0, ∂x ∂y ∂z ∂t v = y 2z

∂v ∂v ∂v ∂v = 0, = y2 = 2 yz , = 0, ∂x ∂z ∂y ∂t w = – (2xyz + yz2)

SQP 2015.6

- /

/#

"

∂w ∂w ∂w ∂w = 0, = - 2 xz + z 2 , = - ( 2 xy + 2 yz ) = - 2 yz , ∂t ∂x ∂y ∂z

(

6

/

)

'

'

ax = 0 + x y ¥ 2 xy + y z ¥ x - (2 xyz + yz 2 ) (0) 2

2

2

= 2 x3 y 2 + x 2 y 2 z a y = 0 + x 2 y ¥ 0 + y 2 z ¥ 2 yz - (2 xyz + yz 2 ) ¥ y 2 = 2 y 3 z 2 - 2 xy 3 z - y 3 z 2 = y 3 z 2 - 2 xy 3 z

(

)

az = 0 + x 2 y ( -2 yz ) + y 2 z -2 xz - z 2 - (2 xyz + yz 2 ) ( -2 xy - 2 yz ) = - 2 x y z - 2 xy z - y z + 4 x y z + 4 xy 2 z 2 + 2 xy 2 z 2 + 2 y 2 z 3 2 2

2 2

2 3

2 2

= 2 x 2 y 2 z + 4 xy 2 z 2 + y 2 z 3 Acceleration is then given by: � a = a x iˆ + a y ˆj + az kˆ

) (

(

) (

)

= 2 x 3 y 2 + x 2 y 2 z iˆ + y3 z 2 - 2 xy3 z ˆj + 2 x 2 y 2 z + 4 xy 2 z 2 + y 2 z 3 kˆ Acceleration at (2, 1, 3) is:

� a ( 2,1,3) = ÈÎ2 ¥ 23 ¥ 12 + 22 ¥ 12 ¥ 3˘˚ i� + ÈÎ13 ¥ 32 - 2 ¥ 2 ¥ 13 ¥ 3˘˚ �j + ÈÎ2 ¥ 22 ¥ 12 ¥ 3 + 4 ¥ 2 ¥ 12 ¥ 32 + 12 ¥ 33 ˘˚ k� = 28iˆ - 3 ˆj + 123kˆ # ' ' * , 9 6 E Answer: The problem is worked out in Example 13.14. _E , ' > * Answer: Refer to Section 14.6.2.

/

/

9

{ 9 9 / /E 8 *9 * / / 9 * H_G $5O 2 ' 9 / / Answer: The problem is worked out in Example 14.20.

� v=

/'

� x � y i+ 2 j. 2 2 x +y x +y

E

2

10. (a) Draw the nature of p – v Answer: Refer to Section 10.3. ? 8 Answer: Refer to Section 10.2. 2 "B ! }8 ' * H $/O E E2 *9

T–s

*

/ * 9

9

*3 ES E &* _ $5O

2

E

$

E

*

@ $ +

E6 H $B

' *

2

ERG

E H "B E # *9 ER ' E

*

6 '

M

B

N

SQP 2015.7

HG

Properties of Saturated Water-Pressure Base 3

X P (MPa)

6

O$/

-

$~O$/

-

$~O$/47

vf

vg

hf

hfg

hg

sf

sfg

sg

}8 2

H E!

0.001177

0.0996

_ RER

HR_ EU

2799.5

E!!UR

3ER_3_

SE3!HU

0.01

!GER

0.001010

H!ESU

H_HER

3_ ER

GR!ES

ES!_H

7.5019

REHGH

Properties of Superheated Steam Table Corresponding to 2 Mpa and 400°C X

3

O$/

-

0.15120

$~O$/

-

$~O$/47

3 !UES

7.1271

Answer: The problem is worked out in Example 10.6. HHE 6 9 * *

/

/

E

Answer: Refer to Sections 3.2.1 and 3.2.2. 6 8 + E Answer: Refer to Section 6.2. ? ' >

/

+ '

Answer: Refer to Section 4.3. 2/ / + E H 3 > PV 2 = C E G 3E # / PV = CE , $ E

*

/

/

/

' /

E 4 E&

Answer: Different processes are shown in Fig. 2.

Fig. 2

*

+ >

E#

/

G / /

SQP 2015.8

- /

/#

"

For the process 2-3, we have:

P2V22 = P3V32 ÊPˆ V2 = Á 3 ˜ Ë P2 ¯

or 4

1/ 2

H4

Ê 2ˆ V3 = Á ˜ Ë 5¯

1/ 2

0.025 = 0.0158 m3

$

W1- 2 = PdV = P(V2 - V1 ) = 500 (0.0158 - 0.01) = 2.9 kJ

Ú

43

$

W2-3 = #

$

*

P2V2 - P3V3 500 ¥ 0.0158 - 200 ¥ 0.025 = = 2.9 kJ n -1 2 -1 34H

W3-1 = PV 1 1 ln

V1 Ê 0.01 ˆ = 500 ¥ 0.01 ln Á = - 4.58 kJ Ë 0.025 ˜¯ V3

$

Wnet = W1- 2 + W2-3 + W3-1 = 2.9 + 2.9 - 4.58 = 1.22 kJ

REFERENCES

1. Michael J. Moran, and Howard N. Shapiro, Fundamentals of Engineering Thermodynamics, 4th Edition, John Wiley& Sons, Inc, 2000 2. Kenneth Wark, Thermodynamics, McGraw-Hill, Fourth Edition, 1995 3. Gordon Rogers and Yon Mayhew, Engineering Thermodynamics Work and Heat Transfer, Fourth Edition, Addison-Wesley, An imprint of Pearson Education, New Delhi, 2001 4. Richard E. Sonntag, Claus Borgnakke, Gordan and J. Van Wylen, Fundamentals of Thermodynamics, Fifth Editon, Jon Wiley & Sons, Inc, 2000 5. P K Nag, Engineering Thermodynamics, Tata McGraw-Hill Publishing Company Limited,1995 6. M C Potter, C W Somerton and Sukumar Pati, Schaum's ouTlines Thermodynamics, Tata-McGrawHill Publishing Company Limited, New Delhi, Second Edition, 2010 7. Richard H Dittman, and Mark W Zemansky, Heat and Thermodynamics, Tata-McGraw-Hill Publishing Company Limited, New Delhi, Seventh Edition, 2007 8. J.B. Jones, P.E., and G.A. Hawkins, P.E., Engineering Thermodynamics, An Introductory Textbook, John Wiley& Sons, Inc, 1986 9. T.D. Eastop and A. McConkey, Applied Thermodynamics for Engineering Technologists, Longman Group limited, 1978 10. Cengel Y.A and Boles M.A., Thermodynamics An Engineering Approach, Tata McGraw-Hill Publishing Company Limited,2006 11. Y.V.C.Rao, An Introduction to Thermodynamics, Universities Press, Revised Edition,2004 12. E. Rathakrishnan, Fundamentals of Engineering Thermodynamics, Prantice-Hall of India Private Limited, New Delhi,2000. 13. C P Arora, Thermodynamics, Tata McGraw-Hill Publishing Company Limited, New Delhi,2000 14. Robert W. Fox and Alan T. McDonald, Introduction to Fluid Mechanics, Fourth Edition, SI Version, John Wiley & Sons Singapore,1994 15. Frank M White, Fluid Mechanics (Special Indian Edition), Tata McGraw-Hill Publishing Company Limited, New Delhi,2007 16. Som, S.K. and Biswas G., Introduction to Fluid Mechanics and Fluid Machines, Tata McGraw-Hill Publishing Company Limited,2004 17. Pijush K. Kundu, Ira M. Cohen, Fluid Mechanics, Third Edition, Academic Press, An Imprint of Elsevier, New Delhi, 2004. 18. Victor L. Streeter and E. Benjamin Wylie, Fluid Mechanics, First SI Metric Edition, McGraw-Hill Book Company, Singapore, 1983 19. Shames I. H., Mechanics of Fluids, McGraw-Hill, Inc.,1992

REF 1.2

Engineering Thermodynamics and Fluid Mechanics

20. Douglas, J.F., Gasiorek, J., M., and Swaffield J.A., Fluid Mechanics, Addison-Wesley,1999 21. Robert L. Daugherty, Joseph B. Franzini and E. John Finnemore, Fluid Mechanics with Engineering Applications, McGraw-Hill Book Company, Singapore, SI Metric Edition, 1989 22. Subramanya K., 1000 Solved Problems in Fluid Mechanics, , Tata McGraw-Hill Publishing Company Limited, New Delhi,2005 23. A. K. Mohanty, Fluid Mechanics, Prantice-Hall of India Private Limited,2004 24. J. A. Fay. Introduction to Fluid Mechanics, MIT Press, Cambridge, MA, 1994 25. J.A. Roberson& C.T.Crowe, Engineering Fluid Mechanics, Fourth Edition, Jaico Publishing House, Mumbai,1999