SOLUTION MANUAL
Munson, Young and Okiishi's Fundamentals of Fluid Mechanics, 9th edition
by Andrew L. Gerhart, John I. Hochstein
SC
O
R
EG
U
ID
ES
, Table of Content
1 Introduction
2 Fluid Statics
3 Elementary Fluid Dynamics—The Bernoulli Equation
4 Fluid Kinematics
5 Finite Control Volume Analysis
SC
6 Differential Analysis of Fluid Flow
7 Dimensional Analysis, Similitude, and Modeling
8 Viscous Flow in Pipes
O
9 Flow over Immersed Bodies
10 Open-Channel Flow
R
11 Compressible Flow
EG
12 Turbomachines
U
ID
ES
, Munson, Young and Okiishi's Fundamentals of Fluid Mechanics 9e
Andrew Gerhart, John Hochstein, Philip Gerhart (Solutions Manual All
Chapters, 100% Original Verified, A+ Grade)
Chapter 1
Section 1.1.1 Solutions
SC
Reserve Problem 1.1.1R
“Drilling mud” is used in hydrocarbon drilling operations to carry debris to the surface and
to both cool and lubricate the drill bit. It is frequently modeled as a Bingham plastic.
Explain why a substance that behaves according to this model does not satisfy the
definition of a fluid.
O
SOLUTION:
The relationship between the applied shear stress and the strain rate of a Bingham plastic
R
can be obtained from many sources, including Section 1.6 of this text. Although it behaves
like a Newtonian fluid for an applied shear stress larger than its yield stress, it exhibits a
strain rate of zero (like a solid) if the applied shear stress is lower than the yield stress.
EG
From Section 1.1 of this text: “A fluid is defined as a substance that deforms continuously
when acted on by a shearing stress of any magnitude.”
Because a Bingham plastic has a finite yield stress, its behavior
does not satisfy the definition of a fluid. Q.E.D.
U
NOTE: Although the question did not require you to think about the implications of a
finite yield stress, they can be significant. Consider the start-up of a drill surrounded by
ID
such a fluid. In general terms, what might the flow look like? Would it require more torque
to start the drill than it would for a Newtonian fluid?
ES
, Reserve Problem 1.1.2R
Many lava flows are well modeled as the flow of a Bingham plastic. Explain why lava
flowing in this manner does not satisfy the definition of a fluid. Describe the influence of
cooling as the lava flows away from the eruption site.
SOLUTION:
The relationship between the applied shear stress and the strain rate of a Bingham plastic
can be obtained from many sources, including Section 1.6 of this text. Although it behaves
SC
like a Newtonian fluid for an applied shear stress larger than its yield stress, it exhibits a
strain rate of zero (like a solid) if the applied shear stress is lower than the yield stress.
From Section 1.1 of this text: “A fluid is defined as a substance that deforms continuously
when acted on by a shearing stress of any magnitude.”
O
Because a Bingham plastic has a finite yield stress, its behavior does not satisfy the
definition of a fluid. Q.E.D
R
As the lava cools, its viscosity will increase
→ reduced speed → reduced rate of shearing → may transition to a solid
EG
→ reduced speed → pileup of fluid → decreased slope → further reduced speed
As the lava cools, the temperature at the surface of the flow may fall to the solidification
temperature resulting in the formation of a solid crust. This crust will slow the rate of
cooling and present a second no-slip boundary, resulting in significant changes in the fluid
mechanics and the heat transfer processes occurring in the flow.
U
NOTE: Once on the surface of the earth, lava flows are gravity driven. If the slope on which
the lava sits is sufficiently steep, the shear stress due to gravity causes the lava to flow
ID
downhill. If the slope is not sufficiently steep, the lava builds into a mound until the surface
of the mound is sufficiently steep to cause the lava flow outward until the surface is once
again not sufficiently steep to induce flow.
ES
Munson, Young and Okiishi's Fundamentals of Fluid Mechanics, 9th edition
by Andrew L. Gerhart, John I. Hochstein
SC
O
R
EG
U
ID
ES
, Table of Content
1 Introduction
2 Fluid Statics
3 Elementary Fluid Dynamics—The Bernoulli Equation
4 Fluid Kinematics
5 Finite Control Volume Analysis
SC
6 Differential Analysis of Fluid Flow
7 Dimensional Analysis, Similitude, and Modeling
8 Viscous Flow in Pipes
O
9 Flow over Immersed Bodies
10 Open-Channel Flow
R
11 Compressible Flow
EG
12 Turbomachines
U
ID
ES
, Munson, Young and Okiishi's Fundamentals of Fluid Mechanics 9e
Andrew Gerhart, John Hochstein, Philip Gerhart (Solutions Manual All
Chapters, 100% Original Verified, A+ Grade)
Chapter 1
Section 1.1.1 Solutions
SC
Reserve Problem 1.1.1R
“Drilling mud” is used in hydrocarbon drilling operations to carry debris to the surface and
to both cool and lubricate the drill bit. It is frequently modeled as a Bingham plastic.
Explain why a substance that behaves according to this model does not satisfy the
definition of a fluid.
O
SOLUTION:
The relationship between the applied shear stress and the strain rate of a Bingham plastic
R
can be obtained from many sources, including Section 1.6 of this text. Although it behaves
like a Newtonian fluid for an applied shear stress larger than its yield stress, it exhibits a
strain rate of zero (like a solid) if the applied shear stress is lower than the yield stress.
EG
From Section 1.1 of this text: “A fluid is defined as a substance that deforms continuously
when acted on by a shearing stress of any magnitude.”
Because a Bingham plastic has a finite yield stress, its behavior
does not satisfy the definition of a fluid. Q.E.D.
U
NOTE: Although the question did not require you to think about the implications of a
finite yield stress, they can be significant. Consider the start-up of a drill surrounded by
ID
such a fluid. In general terms, what might the flow look like? Would it require more torque
to start the drill than it would for a Newtonian fluid?
ES
, Reserve Problem 1.1.2R
Many lava flows are well modeled as the flow of a Bingham plastic. Explain why lava
flowing in this manner does not satisfy the definition of a fluid. Describe the influence of
cooling as the lava flows away from the eruption site.
SOLUTION:
The relationship between the applied shear stress and the strain rate of a Bingham plastic
can be obtained from many sources, including Section 1.6 of this text. Although it behaves
SC
like a Newtonian fluid for an applied shear stress larger than its yield stress, it exhibits a
strain rate of zero (like a solid) if the applied shear stress is lower than the yield stress.
From Section 1.1 of this text: “A fluid is defined as a substance that deforms continuously
when acted on by a shearing stress of any magnitude.”
O
Because a Bingham plastic has a finite yield stress, its behavior does not satisfy the
definition of a fluid. Q.E.D
R
As the lava cools, its viscosity will increase
→ reduced speed → reduced rate of shearing → may transition to a solid
EG
→ reduced speed → pileup of fluid → decreased slope → further reduced speed
As the lava cools, the temperature at the surface of the flow may fall to the solidification
temperature resulting in the formation of a solid crust. This crust will slow the rate of
cooling and present a second no-slip boundary, resulting in significant changes in the fluid
mechanics and the heat transfer processes occurring in the flow.
U
NOTE: Once on the surface of the earth, lava flows are gravity driven. If the slope on which
the lava sits is sufficiently steep, the shear stress due to gravity causes the lava to flow
ID
downhill. If the slope is not sufficiently steep, the lava builds into a mound until the surface
of the mound is sufficiently steep to cause the lava flow outward until the surface is once
again not sufficiently steep to induce flow.
ES
