1
T.G.PACKIA RAJ
M.E
.
, (Ph.D),
Asst. Professor
, Depar
t
ment of
Mechanical
Engi
n
eeri
n
g,
The Rajaas
E
n
gineeri
n
g College,
Vadakkangulam
.
ME
2204
FLUID
MECHANICS
AND
MACHINERY
T
w
o
Marks
Questions
&
Ans
w
ers
UNIT
I
: INTRODUCTION
1.
Define
density
or
mass
density.
Density
of
a
fluid
is
d
efi
n
ed
as
the
ra
t
io
of
the
mass
of
a
fl
u
id
to
its
volume.
Densit
y
,
ρ
=
mass/volume
(Kg/m
3
)
ρ
w
a
t
e
r
=
1000
Kg/m
3
2.
Define
specific
weight
or
weight
density.
Specific
weight
or
weight
density
o
f
a
fluid
is
defined
as
t
he
ratio
be
t
ween
the
weight
of
a
fluid
to
i
t
s
volume.
Specific
w
e
ight,
γ
=
w
e
ight/volume
(N/m
3
)
γ
=
ρg
γ
w
at
er
=
9810
N/m
3
3.
Define
spec
ific
volume.
Specific
volume
of
a
fluid
is
defined
as
the
vol
u
me of
fluid
o
ccupied
by
an
unit
wt
or
unit
mass
of
a
fluid.
Specific
volume
vs
=
volume/
w
t
=
1/γ
=
1/ρg

for
liquids
Specific
volume
vs
=
volume/
mass
=
1/ρ

for
gases
4.
Define
dyn
amic
viscosi
ty
.
Viscosity
is
defined
as
the
property
of
fluid
which
offers
resistance
to
the
mov
e
ment
o
f
one
layer
of
fluid
over
another
adjacent
layer
of
the
fluid.
du
ζ
=
μ



d
y
μ
–
d
y
na
m
ic
v
iscosity
or
v
iscosity
or
coeffici
e
nt
o
f
v
is
cosity
(N

s/
m
2
)
1
N

s/m
2
=
1
Pa

s
=
10
Poise
5.
Define
Kinematic
viscosity.
It is
defined
as
the
ratio
between
the
dynamic
vi
s
c
osity
and
d
ensity
of
fluid.
ν
=
μ/ρ
(m
2
/s)
1
m
2
/s
=
10000
Stokes
(or)
1
stoke
=
10

4
m
2
/s
6.
Types
of
fluids.
Ideal
fluid,
R
eal
fluid,
N
e
wtonian
flui
d
,
Non

Newt
o
nian
fluid,
I
d
eal
Plastic
fluid.
7.
Define
Compressibility.
It is
defined
as
the
ratio
of
volumetr
i
c
strain
to
compressive
stress.
Compress
i
bilit
y
,
β =
(d
Vol/
Vol)
/ dp
(m
2
/N)
2
T.G.PACKIA RAJ
M.E
.
, (Ph.D),
Asst. Professor
, Depar
t
ment of
Mechanical
Engi
n
eeri
n
g,
The Rajaas
E
n
gineeri
n
g College,
Vadakkangulam
.
8.
Define
Surface
Tension.
Surface
tension
is
defi
n
ed
as
the
tensile
force
a
c
ting
on
the
surface
of
the
liquid
in
contact
with
a
gas
or
on
the
surface
between
two
immiscible liquids
such
that
the
contact
sur
f
ace
behaves
like
a
m
e
mbrane
under
tension.
Surface
Tension,
σ
=
Force/Length
(N/m)
σ
w
a
t
e
r
=
0.0725
N/m
σ
M
e
r
c
u
r
y
=
0
.
52
N/m
9.
Surface
tension
on
li
q
uid
droplet,
σ
=
pd/4
Surface
tension
on
a
h
o
llow
bubble,
σ
=
pd/8
Surface
tension
on
a
li
q
uid
jet,
σ
=
pd/2
σ
–
surface
t
ension
(N/m)
d
–
diameter
(m)
p
–
pressure
inside
(N/m
2
)
p
total
=
p
i
n
si
d
e
+
p
atm
p
atm
=
101.325
x
10
3
N/m
2
10.
Define
Capillarity.
Capillarity
is
defined
as
a
phenomenon
of
rise
or
fall
of
a
l
i
quid
surface
in
a
sma
l
l
tube
relative
to
the
adj
a
c
ent general
level
of
liq
u
id
when
the
tube
is
h
e
ld
vertically in
the
liquid.
T
he
rise
of
liquid
surface is
known
as
capillary r
i
se
while
the
fall
of
liquid
surface
is
known
as
c
a
pillary
depression.
Capillary
R
i
se
or
fall,
h
=
(4
σ
cosθ)
/ ρgd
θ
=
0
for
glass
tube
and
water
θ
=
130º
for
glass
tube
and
mercury
11.
Define
Vapour
Pressure.
When
vaporization
tak
e
s
place,
the
molecules
start
accumulating over
the
free
liquid
surface
exerting
pressure
on
the
liquid
surface. This
pres
sure
is
known
as
Vapour
pressure
of
the
liquid.
12.
Define
Control
Volume.
A
control
volume
m
a
y
be
defined
a
s
an
identi
f
ied volume
f
ixed
in
space.
The
boundaries around
the
control
volume
are
ref
e
rred
to
as
control
surfaces.
An
open
system
is
also
refer
red
t
o
as
a
cont
r
ol
volume.
13.
Write
the
c
o
ntinuity
equation.
The
equation
based
on
the
principle
of
conservation
of
mass
is
c
a
lled
continuity
equation.
δu/δx
+
δv/
δ
y
+
δ
w
/δz
= 0

three
dimensional
flow
δu/δx
+
δv/
δ
y
=
0

two
dimensional
flow
Q
=
a
1
v
1
=
a
2
v
2

one
dimensional
flow
14.
List
the
types
of
fluid
f
l
o
w.
Steady
and
unsteady
flow
Uniform
and
non

unifo
r
m
flow
Laminar
and
Turbulent
fl
ow
Compressible
and
incompressible
f
l
o
w
Rotational
and
ir

rotational
flow
One,
Two
a
nd
Three
dimensional
flow
3
T.G.PACKIA RAJ
M.E
.
, (Ph.D),
Asst. Professor
, Depar
t
ment of
Mechanical
Engi
n
eeri
n
g,
The Rajaas
E
n
gineeri
n
g College,
Vadakkangulam
.
15.
Define
Steady
and
Unsteady
flow.
Stea
d
y
flow
Fluid
flow
is
said
to
b
e
steady if
at
any
point
in
the
fl
owing fluid
various
characteris
t
ics
such
as
velocity,
density,
pressur
e
,etc
do
not
change
with
time.
∂V/∂t
=
0
∂p/∂t
=
0
∂
ρ
/
∂t
=
0
Unstea
d
y
f
l
ow
Fluid
flow
is
said
to
b
e
unsteady if
at
any
point
flowing
fluid
any
o
ne
or
all
characteris
t
ics
which
d
e
scribe
the
b
ehaviour
of
the
fluid
in
m
otion
chan
g
e
with
time.
∂V/∂t
≠
0
∂p/∂t
≠
0
∂
ρ
/
∂t
≠
0
16.
Define
Unif
orm
and
Non

uniform
flow.
Uniform
fl
o
w
When
the
velocity
of
flow
of
fluid
does
not
change
b
oth
in
dir
e
ction and
magnitude
from
point
to
point
in
the
flowing
fluid
for
any
given
instant
of
time,
t
h
e
flow
is
said
t
o
be
uniform.
∂V/∂s
=
0
∂p/∂s
=
0
∂
ρ
/
∂s
=
0
Non

uniform
flow
If
the velocity
of
flow
of
f
luid chang
e
s
from
point
to
point
in
t
h
e flowing
fluid
at
any
instant,
the
f
low
is
said
t
o
be
non

uniform
flow.
∂V/∂s
≠
0
∂p/∂s
≠
0
∂
ρ
/
∂s
≠
0
17.
Compare
L
a
minar
and
Turbulent
fl
o
w.
Laminar
and
T
urbulent
fl
o
w
A
flow
is
said
to
be
laminar
if
Reynolds number
is
less
than
2000
for
pi
p
e
flow.
Laminar
flow
is
possi
bl
e
only
at
low
velocities
and
high
viscous
fluids.
In
laminar
type
of
flo
w
,
fluid
particles
move
in
lam
i
nas
or
layers
gliding
smoo
t
hly
ove
r
the
adjacent
la
y
er.
Turbulent
flow
In
Turbulent
flow,
the
f
l
o
w
is
possible
at
both
velocities
and
low
viscous
f
luid. The
flow
is
said
t
o
be
turbulent if
Reyno
l
ds number
is
greater
than
4000
for
pipe
flow.
In
Turbulent
type
of
flow
fluid,
particl
e
s
move
in
a
zig
–
zag
m
anner.
18.
Define
Compressible
a
n
d
incompressible
flow
Compress
i
ble
fl
o
w
The
compressible flow
is
that
type
of
flow
in
which
the
density
of
the
fluid
changes
fr
o
m
point
to
point
i.e.
t
h
e
density
is not
co
n
s
t
a
nt
for
the
fluid.
It
is
e
xpressed
in
kg/sec.
ρ
≠
consta
n
t
Incompressible
fl
o
w
The
incompressible
fl
o
w
is
that
ty
p
e
of
flow
in
which
the
density
is
c
o
nstant
for
the
fluid
f
low.
Liquids
are
generally
incompressible.
It
is
expressed
in
m
3
/s.
ρ
=
constant
4
T.G.PACKIA RAJ
M.E
.
, (Ph.D),
Asst. Professor
, Depar
t
ment of
Mechanical
Engi
n
eeri
n
g,
The Rajaas
E
n
gineeri
n
g College,
Vadakkangulam
.
19.
Define
Rotational
and
Ir

rotational
fl
o
w.
Rotational
flow
Rotational
flow
is
that
type
of
flow
in
which
the
fluid
particles
while
flowi
n
g
along
stream
lines
and
also
ro
t
ate
about
t
h
eir
own
axis.
Ir

rotational
fl
o
w
If
the
fluid
p
articles
are
flowing
alo
n
g
stream
lines
and
do
not
rotate
about
the
ir
own
axis
that
type
of
flow
is
called
as
ir

rotational
flow
20.
Define
One,
Two
and
Three
dimensional
flow.
One
dimensional
fl
o
w
The
flow
parameter
such
as
velocity
is
a
function
of
time
and
one
space
co

ordinate
only.
u
=
f
(x),
v
=
0
&
w =
0.
T
w
o
d
ime
n
sional
fl
o
w
The
velocity
is
a
func
t
i
o
n
of
time
and
two
rectangular
space
co

ordinates.
u
=
f
1
(x
,
y
),
v
=
f
2
(x
,
y
)
&
w =
0
.
Three
dimensional
flow
The
velocity
is
a
func
t
i
o
n
of
time
and
three
mutually
perpendicular
dir
e
ctions.
u
=
f
1
(x
,
y
,z),
v
=
f
2
(x
,
y
,z)
&
w =
f
3
(x
,
y
,z
)
.
21.
Write
the
Bernoulli’s
eq
u
ation
appli
e
d
between
two
sections
p
1
/
ρg
+
v
2
/2g
+
Z
=
p
/ρg
+
v
2
/2g
+
Z
1
1
2
2
2
p/ρg
=
pressure
h
e
ad
v
2
/2g
=
kinetic
head
Z
=
dat
u
m
head
22.
State
the
assumptions
u
s
ed
in
deriv
i
ng
Bernoulli
’
s
equation
Flow
is
ste
a
dy;
Flow
is
laminar;
Flow
is
irro
t
ational;
Flow
is
inc
o
mpressible;
Flui
d
is
ideal.
23.
Write
the
Bernoulli’s
eq
u
ation
appli
e
d
between
two
sections
with
losses.
p
1
/ρg
+
v
2
/2g
+
Z
=
p
/ρg
+
v
2
/2g
+
Z
+
h
1
1
2
2
2
l
o
s
s
24.
List
the
i
n
st
r
uments
works
on
the
b
a
sis
of
Bern
o
ulli’s
equati
o
n.
Venturi
meter;
Orifice
mete
r;
Pitot
tube.
25.
Define
Impulse
Momen
t
um
Equation
(or)
Mom
e
ntum
Equation.
The
total
fo
r
c
e
acting
on
fluid
is
eq
u
al
to
rate
of
change
of
momentum.
According
to
Newton’s
second
law
o
f
motion,
F
=
ma
F
dt
=
d(mv)
5
T.G.PACKIA RAJ
M.E
.
, (Ph.D),
Asst. Professor
, Depar
t
ment of
Mechanical
Engi
n
eeri
n
g,
The Rajaas
E
n
gineeri
n
g College,
Vadakkangulam
.
UNIT
II :
FLOW
THROUGH
CIRCULAR
CONDU
I
TS
1.
Mention
the
range
of
Reynold’s
number
for
laminar
and
turbulent
flow
in
a
pipe.
If
the
Rey
n
old,s number
is
less
t
han
2000,
the
flow
is
laminar.
But
if
t
h
e
Reynold’s
number
is
greater
than
4
000,
the
fl
o
w
is
turbul
e
nt
flow.
2.
What
do
es
Haigen

Poiseulle
equation
refer
to?
The
equati
o
n
refers
to
t
he
value
of
loss
of
he
a
d
in
a
pipe
of
length
‘
L
’
due
to
viscosity
in
a
laminar
flow.
3.
What
is
Ha
g
en
poiseuill
e
’s
formula?
(P
1

P
2
)
/ ρg
= h
f
=
32
µ
Ū
L
/ ρgD
2
The
expression
is
k
n
own
as
Hagen
poiseuille
fo
rm
ula.
Where
P
1

P
2
/ ρg
=
=
=
ioss
=
潦
=
p牥ssu牥
=
桥慤h
Ū=
=
Ave牡ge
=
velocity,
µ
=
Coefficient
of
viscosity,
L
=
Length
of
pipe
D
=
Diame
t
er
of
pipe,
4.
Write
the
expression
for
shear
stress?
Shear
stre
s
s
ζ
=

(∂p/∂
x
)
(r/2)
ζmax
=

(∂p/∂x)
(R/
2)
5.
Give
the
formula
for
ve
l
ocity
distrib
u
tion:

The
formula
for
velocity
distribution
is
given
as
u
=

(¼
µ)
(
∂p/∂x)
(R
2

r
2
)
Where
R
=
Radius
of
t
h
e
pipe,
r
=
Radius
of
the
fluid
element
6.
Give
the
e
q
uation
for
average
velocity
:

The
equati
o
n
f
or
average
velocity
is
given
as
Ū
=

(1/8µ)
(∂p/∂x)
R
2
Where
R
=
Radius
of
t
h
e
pipe
7.
Write
the
relation
between
Um
a
x
and
Ū?
Umax
/ Ū
=
{

(¼
µ)
(∂
p
/∂x)
R
2
}
/ {

⅛
µ
(∂p
/
∂x)
R
2
}
Umax
/ Ū
=
2
8.
Give
the
expression
for
the
coeffici
e
nt
of
friction
i
n
viscous
flow?
Coefficient
o
f
friction
be
t
ween
pipe
and
fluid
in
viscous
flow
f
=16/
Re
Where,
f =
Re
=
Reyno
l
ds
number
9.
What
are
t
he
factors
t
o
be
dete
r
mined
when
viscous
fluid
flows
t
h
rough
the
circular
p
ip
e
?
The
factors
t
o
be
determined
are:
i.
Vel
ocity
dis
t
ribution
acr
o
ss
the
s
e
cti
o
n.
ii.
Ratio
of
maxim
u
m
velo
c
ity
to
the
average
velocity.
iii.
Shear
stress
distribu
t
i
o
n.
iv.
Drop
of
pressure
for
a
given
length.
6
T.G.PACKIA RAJ
M.E
.
, (Ph.D),
Asst. Professor
, Depar
t
ment of
Mechanical
Engi
n
eeri
n
g,
The Rajaas
E
n
gineeri
n
g College,
Vadakkangulam
.
10.
Define
kinetic
energy
correction
fact
o
r?
Kinetic
ene
r
gy
factor
is
defined
as
t
he
r
atio
of
t
he
kinetic
e
nergy
of
the
flow
p
e
r
sec
based
o
n
actual
velocity
across
a
section
to
the
kinetic
e
nergy
of
the
flow
per
sec
based
on
average
ve
l
ocity
across
the
same
section.
It is
d
enoted
by
(α).
K.
E
factor
(α)
=
K.E
p
er
sec
bas
e
d
on
actual
veloc
ity
/
K
.
E
per
sec
based
on
Average
ve
l
ocity
11.
Define
momentum
correction
factor
(
β):
It
is
defin
e
d
as
the
ratio
of
momentum
of
t
h
e
flow
per
sec
based
on
actual
velocity
to
the
momen
t
um of
the
flow
per
sec
based
on
av
erage
vel
o
city
across
t
he
section.
β=
Momen
t
um
per
sec
based
on
actual
velocity/M
o
m
entum Per
sec
based
on
average
ve
l
ocity
12.
Define
Boundary
layer.
When a
real
fluid
flow
passed
a
solid
boundary,
fluid
layer
is
adhered
to
the
solid
boundary.
Due
to
adhesion
fluid
undergoes retardation ther
eby
d
e
veloping a
small
region
in
t
h
e
immediate vicinity
of
the
boundary.
This
region
is
known
as
boundary
layer.
13.
What
is
mean
by
boundary
layer
gr
o
wth?
At
subsequ
e
nt
points
d
o
wnstream
of
the
leading
edge, the
boundary
layer region
increases
b
ecause
t
he
retarded
fluid
is further
r
e
tarded.
This
is referred
as growth
of
boundary
layer.
14.
Classificati
o
n
of
bound
a
ry
layer.
(i)
Laminar
boundary
layer,
(ii)
Transition
z
o
ne,
(iii)
Turbule
n
t
boundary
layer.
15.
Define
Laminar
boundary
layer.
Near
the
leadi
ng
edge
of
the
surface of
the
plate
the
thickn
e
ss
of
boun
d
ary
lay
e
r
is
small
and
flow
is
lami
n
ar.
This
la
y
er
of
fluid
is
said
to
be
l
a
minar
boundary
layer.
The
length
of
the
plate from
the
le
a
ding
edge, upto
which
laminar
bou
n
dary
layer
exists
is
called
as
lami
n
ar
zone.
In
t
his
zone
the
velocity
profile
is
par
ab
olic.
16.
Define
transition
zone.
After
laminar
zone,
the
laminar
boundary layer
becomes unstable
and
t
he
fluid
motion
transformed
to
turbulent
b
o
undary
lay
e
r. This
sh
o
rt
length
over
which
t
h
e
cha
nges
taking
place
is
called
as
tr
a
nsition
zon
e
.
17.
Define
Turbulent
boun
d
ary.
Further
d
o
wnstream
of
transiti
o
n zone,
the
boundary
layer
is
tur
b
ulent
and
continuous
t
o
grow
in
thickness.
T
h
is
layer
of
boundary is
called
turbule
n
t
boundary
layer.
18.
Define
Laminar
sub
Layer
In the
turbulent
boundary
layer
zon
e
,
adjacent
to
the
solid
s
u
rface
of the
plate
the
velocity
var
i
ation
is
in
f
l
u
enced by
v
i
scous
eff
e
c
t
s.
Due
to
very
small
thickness,
t
he
velocity
distribution
is
almost
linear.
This
region
i
s
known
as
laminar
sub
layer.
7
T.G.PACKIA RAJ
M.E
.
, (Ph.D),
Asst. Professor
, Depar
t
ment of
Mechanical
Engi
n
eeri
n
g,
The Rajaas
E
n
gineeri
n
g College,
Vadakkangulam
.
19.
Define
Boundary
layer
T
hickness.
It
is
defined
as
the
distance
from
t
he
solid
b
o
undary
measured
in
y

direction
to
the
point,
w
here
the
velocity
of
fl
u
id
is
approximately equal
to
0.99
times
the
free
stream
vel
o
city
(U)
of
the
fluid.
It is
denoted
by
δ.
20.
List
the
various
types
of
boundary
layer
thickness.
Displace
m
ent
thickn
e
s
s
(
δ*),
M
o
m
entum
thickn
e
ss(θ),
Ener
g
y
thickness
(
δ**)
21.
Define
displacement
thickness.
The
displ
a
cement
thickness
(δ)
is
d
efined
as
t
h
e
distanc
e
b
y
which the
boundary
should
be
displaced
to
compensate for
the
reduction
in
flow
rate
on
account
of
boundary
layer
formati
o
n.
δ*
=
∫
[
1
–
(u/U)
]
d
y
22.
Define
momentum
thickness.
The
m
o
me
n
tum thickness
(θ)
is
defined
as
the
distance
by
which
the
boun
dary
should
be
d
isplaced
to
compensate
for
the
re
d
uction
in
momentum
of
the
flowing
fluid
on
account
of
bou
n
dary
layer
f
o
rmation.
θ
=
∫
[
(u/U)
–
(u/U)
2
]
d
y
23.
Define
energy
thickness
The
energy
thickness
(
δ**)
is
defined
as
the
distance
by
which
the
bo
undary
should
be
displac
e
d
to
compe
n
sate
for
the
reduction
in
kinetic
ene
r
gy
of
the
fl
o
wing
fluid
on
account
of
boundary
layer
format
i
on.
δ**
=
∫
[
(u
/
U)
–
(u/U)
3
]
dy
24.
What
is
meant
by
energy
loss
in
a
pi
p
e?
When
the
fluid
flows
t
h
rough a
pipe,
it
loo
ses
some
energy
or
head
due
to
frictional
r
e
sistance a
n
d
other
reasons.
It
is
called
ene
r
gy
loss.
The
losses
a
r
e
classified
as;
Major
losses
and
Minor
losses
25.
Explain
the
major
loss
e
s
in
a
pipe.
The
major
energy
losses
in
a
pi
p
e
is
mainly
due
to
the
fr
ictional
resistance
caused
by
t
he
shear
fo
r
c
e
between
the
fluid
par
t
icles
and
b
o
undary
walls
of
the
p
ipe
and
also
d
u
e
to
viscosi
t
y
of
the
fluid.
26.
Explain
mi
n
or
losses
in
a
pipe.
The loss
o
f
energy
or
head
due
to
change
of
velocity
of
the
flowing
flui
d
in
magnitude
or
direction
is
called
minor
losses.
It
includes: sudden
expansion
of
the
pipe,
sudd
e
n
contracti
o
n of
the
pipe,
bend
in
a
pipe,
pipe
fittings
and
o
bstruction in
the
pipe,
etc.
27.
State
Darcy

Weisbach
equation
OR
What
is
t
he
expression
for
head
loss
due
to
friction?
h
f
=
4flv
2
/
2
gd
where,
h
f
=
Head
loss
d
ue
to
friction
(m),
L
=
Length
of
the
pipe
(m
),
d
=
Diamet
e
r
of
the
pipe
(m),
V
=
Velocity
of
flow
(m/sec)
f =
Coeffici
e
nt
of
friction
8
T.G.PACKIA RAJ
M.E
.
, (Ph.D),
Asst. Professor
, Depar
t
ment of
Mechanical
Engi
n
eeri
n
g,
The Rajaas
E
n
gineeri
n
g College,
Vadakkangulam
.
28.
What
are
the
factors
in
fl
uencing
the
frictiona
l
loss
in
pipe
f
l
o
w?
Frictional
r
e
sistance
for
the
turbulent
flow
is,
i.
Proportional
to
v
n
where
v
varies
from
1.5
to
2.0.
ii.
Proportional
to
the
density
of
fluid.
iii.
Proportional
to
the
area
of
surface
in
contact.
iv.
Independent
of
pressure.
v.
D
epend
on
the
nature
of
the
surface
in
contact.
29.
Write
the
expression
for
loss
of
head
due
to
sud
d
en
enlargement
of
the
pipe.
h
exp
=
(V
1

V
2
)
2
/2g
Where,
h
e
x
p
=
Loss
of
head
due
to
sudden
e
nlargement
of
pipe.
V
1
=
Veloci
t
y
of
flow
at
pipe
1;
V
2
=
Veloci
ty
of
flow
at
pipe
2.
30.
Write
the
expression
for
loss
of
head
due
to
sud
d
en
contraction.
h
con
=0.5
V
2
/2g
h
con
=
Loss
of
head
due
to
sudden
contraction.
V
=
Velocity
at
outlet
of
pipe.
31.
Write
the
expression
for
loss
of
head
at
the
entr
a
nce
of
the
pip
e.
hi
=0.5
V
2
/2g
hi
=
Loss
of
head
at
ent
r
ance
of
pip
e
.
V
=
Velocity
of
liquid
a
t
inlet
of
the
pipe.
32.
Write
the
expression
for
loss
of
head
at
exit
of
the
pipe.
ho
=
V
2
/2g
where,
ho
=
Loss
of
he
a
d
at
exit
of
the
pipe.
V
=
Velocity
of
liquid
at
inlet
and
outlet
of
the
pi
p
e.
33.
Give
an
ex
p
ression
for
loss
of
head
due
to
an
o
b
struction
in
pipe
Loss
of
he
a
d
due
to
an
obstruction
=
V
2
/ 2g
(
A/
Cc
(A

a
)

1
)
2
Where,
A
=
area
of
pipe,
a
=
Max
ar
e
a
of
obstruc
t
ion,
V
=
Velocity
of
liquid
in
pipe
A

a
=
Area
o
f
flow
of
li
q
uid
at
sec
t
i
o
n
1

1
34.
What
is
co
m
pound
pipe
or
pipes
in
series?
When
the
pipes
of
diffe
r
ent
length
and
different
diameters are
connect
e
d end
to
end,
then
t
h
e
pipes
are
called
as
c
o
mpound
pipes
or
pipes
in
series.
35.
What
is
mean
by
paralle
l
pipe
and
write
the
governing
equati
o
ns.
When
the
pipe
divides
into
two
or
more
branches and
again
join
together
downstream
to
form a
single
pipe
t
h
en it
is
call
e
d
as
p
ipes
in
parallel.
T
he governing
equations
a
r
e:
Q
1
=
Q
2
+
Q
3
h
f1
=
h
f2
36.
Define
equi
valent
pipe
a
nd
write
the
equation
to
obtain
equivalent
pipe
diameter.
The
single
pipe
replaci
n
g
the comp
o
und
pipe
with
same
di
a
m
eter
with
o
ut
change
in
discharge
and
head
l
o
ss
is
known
as
equival
e
nt
pipe.
L
=
L
1
+
L
2
+
L
3
5
5
5
(L/d
5
)
=
(L
1
/d
1
)
+
(L
2
/d
2
)
+
(L
3
/d
3
)
9
T.G.PACKIA RAJ
M.E
.
, (Ph.D),
Asst. Professor
, Depar
t
ment of
Mechanical
Engi
n
eeri
n
g,
The Rajaas
E
n
gineeri
n
g College,
Vadakkangulam
.
37.
What
is
meant
by
Moo
d
y’s
chart
and
what
are
the
uses
of
Moody’s
chart?
The
basic
chart
plotted
against
Darcy

Weisbach
friction
factor
against
Reynold’s
Number
(Re)
for
the
variety
of
relative
roughness
and
flow
regimes. The
relative
r
oughness
is
the
ratio
of
the
mean
height
of
roughness
of
the
pipe
a
nd
its
diameter
(
ε
/D).
Moody’s
diagram
is
accurate
to
ab
o
ut 15%
for
d
esign
calculations
and
u
s
ed for
a
large
number
of
applications. It
c
a
n
be
used
for
non

circ
u
lar
conduits
and
also
f
o
r
open
chan
n
els.
38.
Define
the
terms
a)
Hy
d
raulic
gradi
e
nt
line
[HGL]
b)
Total
Energy
line
[TEL]
Hydraulic
gradient
line:
I
t
is
defined
as
the
line
which
gives
the
sum
of
pressure
head
and
datum
head
of
a
flowing
fluid
in
a
p
i
p
e
with
resp
e
c
t
the
refer
e
nce
line.
HGL
=
Sum
of
Pressure
Head
and
Datum
head
Total
ener
g
y
line:
Total
energy
lin
e
is
defined as
the
line
which
gives
the
sum
of
pressure
head,
dat
u
m
head
and
kinetic
h
ead
of
a
flowing
fluid
in
a
pipe
with
respect
to
some
reference
li
n
e.
TEL
=
Sum
of
Pressure
Head,
Datum
head
and
Velocity
h
e
ad
10
T.G.PACKIA RAJ
M.E
.
, (Ph.D),
Asst. Professor
, Depar
t
ment of
Mechanical
Engi
n
eeri
n
g,
The Rajaas
E
n
gineeri
n
g College,
Vadakkangulam
.
UNIT
III :
DIMENSIONAL
ANALYSIS
1.
Define
dimensional
analysis.
Dimensional
analysis
is
a
mathemat
ic
al
tech
n
iq
u
e
which
makes
use
of
t
he
study
of
dimensions
as
an
aid
to
soluti
o
n
of
several
engineeri
n
g
problems. It
plays
a
n
important
role
in
research
work.
2.
Writ
e
the
uses
of
di
m
ension
analysis?
•
It helps
in
t
e
sting
the
dimensional
homogeneity
of
any
equation
of
fluid
motion.
•
It helps
in
d
eriving
equations
expressed
in
terms
of
non

dimensional
par
a
meters.
•
It
helps
in
planning
model
tests
and
presenting
experimental
results
in
a
systematic
manner.
3.
List
the
p
r
imary
and
d
erived
quantities.
Primary
or
Fundamental quantities:
The
var
i
ous
physic
a
l
quantities
used
to
describe
a
given
phenomenon can
be
described
by
a
set
of
quantities
which
are
indepe
ndent
of
each
ot
h
er. These
q
uantities
are
known
as
f
undamental
quantities
o
r
primary
qu
a
ntities.
Mass
(M),
Length
(L),
Time
(T)
and
T
emperature
(
θ)
are
the
fundamental
quantities.
Secondary or
Derived
quantities:
All
other
quantities
s
u
ch
as
area,
volum
e
,
velocity,
acceleration, energy,
p
o
wer,
etc
are
termed
a
s
derived
quantities
o
r
secondary
quantities
b
e
cause
they
can
be
expressed
by
primary
qua
nti
t
ies.
4.
Write
the
dimensions
for
the
foll
o
wings.
D
y
namic
v
i
scosity
(μ)
–
ML

1
T

2
,
Force
(F)

MLT

2
,
Mass
density
(
ρ)
–
ML

3
,
Po
w
er
(P)

M
L
2
T

3
5.
Define
dimensional
homogeneity.
An
equation
is
said
to
be
dimensionally
homog
e
neous if
the
dimensions
of
the
terms
on
its
LHS
are
same
as
the
dimensions
of
the
terms
on
its
RHS.
6.
Mention
the
methods
available
for
dimensional
analysis.
Rayleigh
m
e
thod,
Bucki
n
ghum
π
me
t
hod
7.
State
Buckingham’s
π
theorem.
It
states
that
“if
there
are
‘n’
variabl
e
s
(both
ind
e
pendent
&
d
ependent
variables)
in
a
physical
phenomenon and
if
these
variables
contain
‘m’
functional
dimensions
and
are
related
by
a
dimensionally
homogeneous equati
o
n,
then
the
variables
are
arranged
in
t
o
n

m
dime
ns
ionless
te
r
ms.
Each
term
is
called
π
term”.
8.
List
the
r
e
peating
variables
used
in
Buckingh
a
m
π
theor
e
m.
Geometric
a
l
Properties
–
l, d, H,
h, etc,
Fl
o
w
Properties
–
v,
a,
g,
ω
,
Q,
etc,
Fluid
Properties
–
ρ,
μ,
γ,
etc.
9.
Define
model
and
pr
o
totype.
The
small
scale
replica
of
an
actual
st
ructure or
the
ma
c
hine
is
kn
o
wn
as
its
Model,
while
the
actual
structure
or
machine
is
called
a
s
its
Prototype. Mostly
models
are
much
smaller
than
the
correspondi
n
g
prototype.
10.
Write
t
h
e
advantages
of
model
analysis.
11
T.G.PACKIA RAJ
M.E
.
, (Ph.D),
Asst. Professor
, Depar
t
ment of
Mechanical
Engi
n
eeri
n
g,
The Rajaas
E
n
gineeri
n
g College,
Vadakkangulam
.
•
Model
test
are
quite
ec
o
nomica
l
and
convenient.
•
Alterations
can
be
conti
n
ued
until
most
suita
b
le
d
esign
is
ob
t
ained.
•
Modification
of
prototype
based
on
t
h
e
model
results.
•
The
information
about
t
he
performance
of
pr
o
totype
can
be
obtained
well
in
advance.
11.
List
the
ty
pes
of
si
milarities
or
s
i
militude
us
e
d
in
model
anlaysis.
Geometric
similarities,
K
inematic
similariti
e
s
,
Dynamic
similar
i
ties
12.
Define
geometric
similarities
It
exists
be
t
ween
the
model
and
p
r
ototype
if
the
ratio
of
c
o
rresponding lengths,
dimensions
in
the
mod
e
l
and
the
p
r
ototype
are
equal. S
u
ch
a
ra
t
io
is
known
a
s
“Scale
Ratio”.
13.
Define
kinematic
similarities
It
exists
be
t
ween
the
model
and
prototype if
the
pat
h
s
of
the
homogeneous
moving
par
t
icles
are
g
e
ometrically similar
and
if
the
ra
t
io
of
the
flow
pr
operties
i
s
equal.
14.
Define
dynamic
similarities
It
exits
b
e
tween
mo
d
el
and
the
prototype
which
are
geometr
i
cally and
kinematically
similar
a
n
d
if
the
ratio
of
all
forces
acting
on
the
model
a
nd
prototy
p
e
are
equal.
15.
Mention
the
various
forces
co
n
s
i
dered
in
fluid
flow.
Inertia
force,
Viscous
fo
rc
e,
Gravi
t
y
force,
Pressure
fo
r
ce,
Surface
Tension
force,
Elasticity
fo
r
ce
16.
Define
model
law
or
similarity
l
a
w.
The
condition
for
existence
of
completely
dy
namic
similarity
betwe
e
n
a
model
and
its
pro
t
ot
ype
are
denoted
by
e
quation
ob
t
ained
from
dimensionl
e
ss
numbers.
The
laws
on
which
the
models
are
designed for
dyn
a
mic
similarity are
called
Model
laws
or
Laws
of
Similari
ty
.
17.
List
the
various
mo
d
el
laws
applied
in
model
analysis.
Reynold’s
=
Model
=
iaw,
Froude’s
=
Model
=
iaw,
Euler’s
=
Model
=
iaw,
Weber
Mo
d
el
Law,
Mach
Model
Law
18.
State
Reynold’s
model
law
For
the
flow,
where
in
a
ddition to
i
n
ertia
force
the
viscous force
is
the
only
other
predominant force,
the
similarity
of
flow
in
t
h
e
model
and
its
pro
to
t
ype
can
be
establish
e
d,
if
the
Renold’s
number
is
same
for
both
the
systems.
This
is
known
a
s
Reynold’s
model
law.
Re
(p)
=
Re
(m)
19.
State
Froude’s
model
law
When
the
f
orces
of
gravity
can
be
considered
t
o
be
the
on
l
y
pred
o
minant force
which
c
ontrols
the
motion
in addition
to the
for
c
e
of inertia,
the
dyn
a
mic
similarities
o
f
the
flow
in
a
ny
two
such
systems
c
a
n
be
es
t
ablished, if
the
Froude
number
for
both
the
system
is
the
same.
This
is
kn
o
wn
as
Froude
Model
Law.
Fr
(p)
=
Fr
(m)
20.
State
Euler’s
model
law
In
a
fluid
system
where
supplied
p
r
essures
are
the
controlling
forces
in
addition
to
inertia
fo
r
c
es
and
ot
h
er
forces
a
r
e
either
enti
r
ely
absent
or
in

signi
f
ic
a
nt
the
Euler’s
12
T.G.PACKIA RAJ
M.E
.
, (Ph.D),
Asst. Professor
, Depar
t
ment of
Mechanical
Engi
n
eeri
n
g,
The Rajaas
E
n
gineeri
n
g College,
Vadakkangulam
.
number
for
both
the
model
and
pro
t
otype
which
known
as
Euler
Model
Law.
21.
State
Weber’s
model
law
When
surf
a
c
e
tension
effect
pred
o
minates in
addition
to
inertia
force
then
the
dynamic
similarity
is
obt
a
ined
by
equating
the
W
eber’s
number
for
both
model
and
its
prototype,
which
is
call
e
d
as
Weber
Model
Law
.
22.
State
Mach’s
model
law
If
in
any
p
h
enomenon
only
the
forces
resulti
n
g
from
ela
s
tic
compression a
r
e
significant
in
addition
to inertia
forces
and
all other
forces
may
be neglected,
then
t
h
e
dynamic
similarity
between
model
and
its protot
y
pe
may
be
ac
hieved
by equating
the
Mach’s
number
for
both
the
systems.
This
is
k
n
own
Mach
Model
Law.
23.
Classify
the
hydraulic
models.
The
hydraulic
models
are
classified
as:
Undisto
r
ted
model
&
Distorted
model
24.
Define
undistorted
model
An
undistorted
model
is t
hat
which
is
geometr
i
cally
similar
to
i
ts
prototype,
i.e.
the
scale
ratio
f
or
corresp
o
nding linear
dimensions
of
the
mo
d
el
and
its
p
rototype
are
sa
m
e.
25.
Define
distorted
model
Distorted
models
are
those
in
which
one
or
more
terms
of
the
mo
d
el
are
not
id
entical
wi
t
h
their
coun
t
erparts
in
t
h
e
prototype.
26.
Define
Scale
effect
An
effect
in
fluid flow t
h
at results
fr
o
m
changing
the
scale,
b
ut
not
the
s
h
ape,
of
a
body
around
which
the
flow
passes.
27.
List
the
advantages
of
distorted
model.
•
The
results
i
n
steeper
water
surface
slopes
and
magnificati
o
n
of
wave
h
eights
in
model
can
be
obtained
b
y
providing
true
vertical
structure
wi
t
h
accuracy.
•
The
model
size
can
be
r
educed
to
l
o
wer
down
the
cast.
•
Sufficient
tr
a
c
tate
force
can be
developed
to
produce
be
d movement
with a
small
model.
28.
Write
the
dimensions
f
o
r
the
followings.
Quantities
Symbol
Unit
Dimension
Area
A
m
2
L
2
Volume
V
m
3
L
3
Angle
Α
Deg.
Or
R
a
d
M
0
L
0
T
0
Velocity
v
m/s
L
T

1
Angular
Ve
l
ocity
ω
Rad/s
T

1
Speed
N
rpm
T

1
Acceleration
a
m/s
2
LT

2
Gravitatio
n
al
Acceleration
g
m/s
2
LT

2
Discharge
Q
m
3
/s
L
3
T

1
Discharge
per
meter
run
q
m
2
/s
L
2
T

1
Mass
Dens
i
ty
ρ
Kg/m
3
M
L
3
Sp.
Weight
o
r
Unit
Weight
N/m
3
M
L

2
T

2
D
y
namic
V
i
scosity
μ
N

s/m
2
M
L

1
T

1
13
T.G.PACKIA RAJ
M.E
.
, (Ph.D),
Asst. Professor
, Depar
t
ment of
Mechanical
Engi
n
eeri
n
g,
The Rajaas
E
n
gineeri
n
g College,
Vadakkangulam
.
Kinematic
viscosity
m
2
/s
L
2
T

1
Force
or
Weight
F
or
W
N
MLT

2
Pressure
or
Pressure
i
ntensity
p
N/
m
2
or
Pa
ML

1
T

2
Modulus
of
Elasticity
E
N/m
2
or
Pa
ML

1
T

2
Bulk
Modu
l
us
K
N/m
2
or
Pa
ML

1
T

2
Workdone
or
Ener
g
y
W
or
E
N

m
ML
2
T

2
Torque
T
N

m
ML
2
T

2
Po
w
er
P
N

m/s
or
J/s
or
Watt
M
L
2
T

3
14
T.G.PACKIA RAJ
M.E
.
, (Ph.D),
Asst. Professor
, Depar
t
ment of
Mechanical
Engi
n
eeri
n
g,
The Rajaas
E
n
gineeri
n
g College,
Vadakkangulam
.
UNIT
I
V : ROTO
DYNAMIC
MACHINES
1.
What
are
fl
u
id
machines
or
Hydraulic
machines?
The
machines which
use
the
liquid
or
gas
for
the
transfer
of
energy
fr
o
m
fluid
to
rotor
or
from
rotor
to
fluid
are
known
as
fluid
machines.
2.
How
are
fluid
machines
classified?
Fluid
machines
are
classified
into
two
categories depending upon
transfer
of
energy:
1.
Turbines
–
hydraulic
energy
is
converted to
mechanical
energy
and
then
electric
a
l
e
n
ergy.
2.
Pumps
–
electrical
e
nergy
is
converted
to
mechanical
energy
and
then
hydraulic
ene
r
gy.
3.
What
are
c
a
lled
turbines?
Hydraulic
turbines
are
t
he
machines
which
use
the
energy
of
water
and convert
it
into
mechanical en
ergy.
The
mech
a
nical energy
developed
by
a
turbine
is
used
in
running
the
electric
a
l
g
e
nerator
which
is
direc
t
ly
coupled
to
t
he
shaft.
4.
What
is
kn
o
wn
as
Euler’s
equation
f
or
turbo

m
a
chines?
The
general
expression
for
the
work
done
per
s
e
cond
on
impell
er
is
ρQ[V
w
1
u
1
+
V
w
2
u
2
]
5.
Define
Gross
Head
of
a
turbine.
The
differe
n
ce
between
head
race
l
e
vel
and
tail
r
ace
level
is
known
as
Gross
Head
6.
Define
Net
head
of
a
tu
r
bine.
It
is
also
called
effective
head
and
is
defined
as
t
he
head
available
at
t
h
e
i
nlet
of
the
turbine.
H
=
H
g
–
h
f
7.
What
are
the
efficie
n
ci
e
s
of
a
turbi
n
e?
Hydraulic
efficiency
Mechanical
efficiency
Volumetric
efficiency
Overall
efficiency
8.
Define
Hydraulic
efficie
n
cy.
It
is
defined
as
the
ratio
of
the
power
given
by
water
to
th
e
runner
of
a
turbine
to
the
power
supplied
by
the
water
at
the
inlet
of
t
h
e
turbine.
Po
w
er
deli
v
ered
to
runner
(runner
p
o
w
er)
η
h
=









Po
w
er
su
p
plied
at
inl
e
t
(
w
ater
p
o
w
er)
Water
power
=
γQH
=
(1/2)
m
v
2
9.
Define
Mechanical
ef
f
iciency.
The
ratio
of
the
power
available at
the
shaft
of
the
turbine
to
the
power
delivered
t
o
the
runn
e
r
is
defined
as
mechanical
efficiency.
Po
w
er
avai
l
able
at
the
shaft
(shaft
p
o
w
er)
η
m
=









Po
w
er
deli
v
ered
to
runner
(runner
p
o
w
er)
15
T.G.PACKIA RAJ
M.E
.
, (Ph.D),
Asst. Professor
, Depar
t
ment of
Mechanical
Engi
n
eeri
n
g,
The Rajaas
E
n
gineeri
n
g College,
Vadakkangulam
.
10.
Define
volumetric
efficiency.
The
ratio
of
the
vo
lume
of
the
water
actually striking the
runner
to
the
volume of
water
supplied
to
the
tu
r
bine
is
de
f
i
n
ed
as
volumetric
efficie
n
cy.
11.
Define
Overall
efficiency.
It
is
defined as
the
ratio
of
the
power
available at
the
shaft
of
the
turbine
to
the
power
su
pplied
by
the
water
at
the
i
n
let
of
the
tu
r
bine.
Po
w
er
avai
l
able
at
the
shaft
(shaft
p
o
w
er)
η
o
=







Po
w
er
su
p
plied
at
inl
e
t
(
w
ater
p
o
w
er)
η
o
=
η
h
η
m
η
v
(or)
η
o
=
η
h
η
m
12.
What
are
an
impulse
turbine
and
a
r
eaction
turbine?
Impulse
Turbine:
If
at the
inlet
of the
turbi
n
e,
the
energy
avai
lable
is only
kinetic
energy,
the
turbine
is
k
n
own
as
impulse
tu
r
bine.
T
h
e
p
ressure at
t
he
inlet
of
t
he
turbine
is
atmosphere.
This
turbine
is
used
for
h
igh
heads.
T
he
water
strikes
the bucket
along
t
h
e tangent
of
the
runner.
Ex:
Pelton
Wheel
Turbine.
Re
action
Turbine:
If
at
the
inlet
of
the
t
u
rbine,
the
water
possesses kinetic
energy
as
well
as
pressure
energy,
the
t
u
rbine
is
k
n
own
as
re
ac
tion
turbi
n
e.
As
the
water
flows
through
the
runner,
the
water
is
under
pressu
r
e
and
the
pressure en
e
rgy
goes
on
ch
anging
i
n
to
kine
t
ic
e
nergy.
The
runner
is
completely
enclosed
in
an
air

t
ight
casing and
t
he
runner and
casing is
completely
full
of
water.
This
turbi
n
e is
used
for
medium
he
a
ds.
Ex:
Francis
Turbin
e
.
13.
Define
Jet
Ratio.
It
is
defined as
the
ratio
of
the
pitch
diameter (D)
of
the
Pelton
wheel
to
t
h
e
diameter
of
the
jet
(d).
It
is
denoted
by
‘m’
and
is
given
as
m
=
D/d
14.
Classificati
o
n
of
hydraulic
turbines:
(a)
Based
on
t
y
pe
of
ener
g
y
available
at
inlet
Impulse
turbine
(Pelton
wheel)
Reaction
tu
r
bi
ne
(Francis
turbine,
K
aplan
turbi
n
e,
Propeller
turbine)
(b)
Based
on
head
available
at
inlet
High
head
turbine
–
[ >
250
m
]

(Pelton
wheel)
Medium
he
a
d
turbine
–
[
60
to
250
m
]

(Francis
t
urbine)
Low
head
turbine
–
[ <
6
0
m
]
–
(Ka
p
lan
turbine,
Prope
ller
turbine)
(c)
Based
on
specific
speed
High
specific
speed
tur
b
ine
–
(Kapl
a
n
turbine,
Propeller
turbine)
Medium
sp
ec
ific
speed
t
urbine

(Francis
turbi
n
e)
Low
specific
speed
turbine

(Pelton
wheel)
(d)
Based
on
direction
of
flow
through
runner
Tangenti
al
flow
turbine
Radial
flow
turbine
Axial
flow
turbine
Mixed
flow
t
urbine
16
T.G.PACKIA RAJ
M.E
.
, (Ph.D),
Asst. Professor
, Depar
t
ment of
Mechanical
Engi
n
eeri
n
g,
The Rajaas
E
n
gineeri
n
g College,
Vadakkangulam
.
15.
Define
Radial
flow
reaction
turbine
a
nd
their
types.
If
water
flows
in
the
radial
direction in
the
turbi
n
e
then
it
is
r
eferred
as
radial
flow
turbine.
Types:
Inward
radial
flo
w
re
a
ction
turb
i
ne:
If
the
water
flows
from
outwar
d
s to
inwards
through the
runner,
the
turbine
is
k
n
own
as
inward
radial
flow
reaction turbine. Here
the
outer
di
ameter of
t
h
e
runner
is
inlet
diamet
e
r whereas
t
he
inner
d
i
a
meter of
t
h
e
runner
is
ou
t
let
diam
eter.
Out
w
ard r
a
dial
fl
o
w
r
e
action turbine:
If
the
w
ater
flows
f
r
om
inwards
to
outwards
through
the runner,
the
t
urbine
is called
as outw
a
rd
radial
flow
reaction
turbine.
Here
the
outer
di
ameter of
t
h
e
runner
is
outlet
diam
e
ter whereas
the
inner
d
i
a
meter
of
t
h
e
runner
is
inlet
diameter.
16.
What
is
mean
by
Draft
T
ube?
The
draft
t
u
be
is
a
pipe
of
gradually increasing
a
rea
which
connects
the
outlet
of
the
runner
t
o
the
tail
race.
One
end of
the
draft
tube
is
con
n
ected
to
the outlet of
the
runner
while
the
other
e
nd
is
sub

merged
below
the
level
of
water
in
the
tail
race.
17.
Why
do
draft
tubes
have
enlarging
p
assage
area
in
the
direc
t
ion
of
flow?
The pressu
r
e
at
the
exit of
the
reaction
turbine
is
generally
l
e
ss than at
m
ospheric
and
this
m
akes the
w
ate
r
NOT
to
discharge
directly to
the
tail
r
a
ce.
By
the
introduction
of
draft
tube,
which has
enlarged
area
in
the
di
r
ection
of
fl
o
w,
the
kinetic
head
reduces
and
pressure
head
increases.
There
by
discharge of
water
to
the
tail
race
safel
y
.
18.
U
ses
of
dra
f
t
tube:
Discharges
water
to
tail
race
safely
Converts
a
large
proportion
of
rejec
t
ed
kine
t
ic
e
nergy
into
useful
press
u
re
energy
Net
head
of
the
turbine
is
increas
e
d.
19.
Types
of
draft
tube:
Conical
draft
tube,
Simple
elbow
tube,
Moody
spreadin
g
tube
and
Elbow
draft
tube
with
ci
r
c
ular
inlet
a
nd
rectangular
outlet.
20.
Define
specific
speed
of
a
turbine.
It
is
d
e
fined
as
the
sp
e
ed
of
the
tu
r
bine
which
is
geometrically similar
and
it
will
develop
unit
power
when
working
u
nder
unit
h
e
ad.
N
s
=
N
√P/
(
H)
5/4
21.
Define
Runaway
speed
of
Turbine.
The
max
speed
reached by
the
turbine
after
the
removal
o
f
the
exter
n
al load
is
called
ru
na
way
speed
of
turbine. The
various
rotating
c
o
mponents
of
the
turbi
n
e
should
be
d
esigned
to
r
emain
safe
at
the
runaw
ay
speed.
22.
List
the
cha
r
acteristic
c
u
rves
of
Hydraulic
turbin
e
.
Main
Char
ac
teristic
Curves
(or)
Co
ns
tant
Head
Curves
Operating
Characteristic
Curves
(or)
Constant
Speed
Curves
Muschel
Curves
(or)
C
o
nstant
Efficiency
Curves
17
T.G.PACKIA RAJ
M.E
.
, (Ph.D),
Asst. Professor
, Depar
t
ment of
Mechanical
Engi
n
eeri
n
g,
The Rajaas
E
n
gineeri
n
g College,
Vadakkangulam
.
2
23.
What
is
roto
dynamic
p
ump?
When
the
i
n
crease
in
p
r
essure
is
d
eveloped by
rotating
i
m
peller
or
by
action
of
centrifugal
f
orce
then
t
h
e
pump
is
called
as
roto
dynamic
pump.
24.
Define
Centrifugal
pump.
Hydraulic
pump
means
it
converts
me
c
hanical
energy
into
hydraulic
e
n
ergy.
If
the
mechanical energy
is
converted
into
pressu
r
e
energy
means
of
cen
t
rifugal
force
acting
on
t
h
e
fluid,
the
hy
draulic
machine
is
called
Centrifugal
Pump.
25.
Define
Specific
spe
e
d
of
a
centrifug
a
l
pump.
The
specific
speed
of
a
centrif
u
gal pump
is
defined
as
the
sp
e
ed
of
a
geometrically
similar
pump
which
would
deliver
1
m
3
/s
against
a
head
of
1
m.
N
s
=
N
√
Q/
(
H)
3/4
(OR)
N
s
=
N
√P/
(
H)
5/4
26.
Efficienci
e
s
of
a
Centrifugal
Pump:
Manometr
i
c
Efficien
c
y
:
The
ratio
o
f
the
man
o
metric
head
to
the
he
a
d
imparted
by
the
impeller
to
the
water
is
kn
o
wn
as
manometric
efficiency.
Manometr
i
c
Head
g
H
m
η
ma
n
o
=








=

Head
imparted
b
y
i
mpeller
to
w
ater
V
w
2
u
2
Head
impar
t
ed
by
impeller
to
water
=
V
w
2
u
2
/g
Mechanical
Efficien
c
y
:
The
ratio
of
the
power
available
at
the
impeller
to
the
power
at
the
s
h
aft
of
t
h
e
c
entrifugal
pump
is
kn
o
wn
as
mechanical
ef
f
ici
e
ncy.
P
o
w
er
at
the
impeller
η
mech
=



Shaft
Po
w
e
r
Power
at
the
impeller
=
workdone
by
impeller
per
sec
=
ρQ
V
w
2
u
2
Overall
Eff
i
cien
c
y
:
The ratio of
power
output
of
the
pump
to
the
power
input
to
the
pump
is
called
as
overall
efficiency.
Weight
of
w
ate
r
lifted
x
Hm
η
o
=







Shaft
Po
w
e
r
27.
Define
Manometric
Head.
The
manometric
head
is
defined
a
s
the
head
against
which
a
centri
f
ugal
pump
has
to
work.
H
m
=
head
imparted
b
y
the
impeller
to
the
w
a
t
er
–
loss
of
head
H
m
=
V
w
2
u
2
/g

loss
of
head
H
m
=
h
s
+
h
d
+
h
fs
+
h
fd
+
v
d
/2g
18
T.G.PACKIA RAJ
M.E
.
, (Ph.D),
Asst. Professor
, Depar
t
ment of
Mechanical
Engi
n
eeri
n
g,
The Rajaas
E
n
gineeri
n
g College,
Vadakkangulam
.
28.
Differentiate
static
head
&
man
o
metric
head.
Sl. No.
Static
Head
Manometr
i
c
Head
1
The vertical
head
dist
a
nce
to
liquid
surface
in
sump
to
overhead
tank.
Total
head
that
must
be
prod
uced
by
pump
t
o
satisfy
the
external
requirements.
2
Loss
of
h
e
ad
in
the
pump
is
not
considered.
The
friction
head
loss
&
kinetic
he
a
d
are
conside
r
ed.
3
H
=
H
s
+
H
d
H
m
=
H
s
+
H
d
+
h
fd
+
v
2
/2g
d
2
2
29.
Minim
u
m
speed
for
starting
a
Centrif
ugal
Pump,
H
m
=
u
2
/2g

u
1
/2g
30.
What
is
mean
by
multi
stage
pump?
If
more
than
one
impell
e
r
is
used
in
pump
then
s
uch
type
is
known
as
multistage
pump.
Impellers
in
series
–
Number
of
impellers
are
mounted
on
a
common
shaft.
This
increases
t
h
e
total
head.
Total
head
=
n
H
m
Impellers
in
parallel
–
Impellers
a
re
mounted
in
separate shaft.
T
h
is
increases
t
h
e
discharge.
Total
disch
a
rge
=
n
Q
31.
Compare
Centrifugal
P
ump
&
Rec
i
procating
P
ump.
Sl. No.
Centrifugal
Pump
Reciprocating
Pump
1
Its
dischargi
ng
capacity
is
more.
Its
discharging
capacity
is
low.
2
It
can
be
us
ed
for
lif
t
ing
highly
visc
o
us
liquids.
It
can
handle
only
pure
water
or
less
viscous
liq
ui
ds.
3
Its
maintenance
cost
is
low.
Its
maintenance
cost
is
h
igh.
4
It can
be
o
p
erated
at
ver
y
high
speed.
High
speed
may
cause
cavitatio
n
s
and
separation.
32.
Define
Priming
of
a
cent
r
ifugal
pump.
Priming
of
a
centrifug
a
l
pump
is
d
efined
as
t
h
e
operation
in
which
t
h
e
suction
pipe,
casing
of
the
pump and
a
por
t
ion
of
the
d
elivery
pipe
up
to
the
d
e
livery
va
l
v
e
is
completely filled
up
fr
o
m
outside
source
with
the
liquid
to
be
raised
by
the
pump
before
starting
the
pump.
33.
Define
cavitation.
Cavitation
is
defined
a
s
the
phe
n
omenon of
formation
of
vapour
bubbles
of
a
flowing
liquid
in
a
region
where
the
pressure of
the
fluid
falls
bel
o
w
its
vapour
pressure
a
n
d
the
sudd
e
n
collapsing of
these
vapour
bubbl
e
s
in
a
regi
o
n
of
higher
pressure.
34.
What
are
pump
characteristics?
Pump
char
ac
teristic means
the
ch
a
racter
i
stic curves
of
a
pump.
Characteri
stic
curves
of
c
e
ntrifugal p
u
mps
are
defined
as
those
curves
which
are
plot
t
ed
from
the
results
of
a
number
of
tests
on
the
centrifugal
p
ump.
These
curves
are
necessary
t
o
predict
the
b
ehaviour
and performa
n
ce
of
the
pump
when
t
h
e
pump
is
working
under
dif
ferent
fl
o
w
rate,
head
and
speed.
19
T.G.PACKIA RAJ
M.E
.
, (Ph.D),
Asst. Professor
, Depar
t
ment of
Mechanical
Engi
n
eeri
n
g,
The Rajaas
E
n
gineeri
n
g College,
Vadakkangulam
.
UNIT
V :
P
O
SIT
I
VE
DISPLACEMENT
MACH
I
NES
1)
What
is
a
r
e
ciprocating
pump?
Reciprocati
n
g
pump
is
a
positive
displ
a
cement
pump.
This
means
the
l
iquid
is
first
sucked
into
the
cyli
n
der
and
then
displac
e
d
or
pushed
b
y
the
thrust
of
a
piston.
2)
What
is
sin
g
le
acting
p
u
mp
and
double
acting
p
ump?
If
the
water
is
in
contact with
one
si
d
e
of
the
pis
t
on
the
pump
then
it
is
known
as
single
ac
t
ing
reciprocati
n
g
pump.
For
one
complete
revolution
one
suction
stroke
and
one
deliver
y
stroke
occ
u
rs.
If
the
water
is
in
cont
a
c
t with
both
sides
of
the
p
iston
the
p
u
mp
then
it
is
called
double
acti
n
g
reciprocating pump.
F
or
one
complete
revolution
two
suction
strokes
and
two
delivery
strokes
occurs.
3)
What
is
Discharge
through
a
Recip
r
o
cating
Pump?
For
Single
acting
Reciprocating
Pump:
Discharge
(
Q
T
)=ALN/60
For
Double
acting
Reciprocating
Pump:
Q
T
=
2
ALN/60
A=Area
of
the
Cyclinder
(
m
2
),
L=Length
of
Stroke
(m),
N=S
p
eed
of
Crank
(rpm)
4)
What
is
the
Workdone
b
y
Reciprocating
Pump
per
sec?
For
Single
acting
Reciprocating
Pump:
Workdone
=
ρgALN(hs+hd)/60
For
Double
acting
Reciprocating
Pump:
Work
done=
2ρgALN(hs+h
d
)/60
Where,
ρ=Density
of
Water
(kg/m
3
),
A=Area
of
the
Cylinder
(
m
2
),
L=
Stroke
Length
(m),
N=Speed
(rpm),
hs,
hd=Suction
and
Deli
very
he
a
d
(m).
5)
Define
slip
a
nd
%
slip.
The difference
between
the
theoretical
discharge
(Q
T
)
and a
c
tual
discha
r
ge
(Q
ac
t
)
is
known
as
slip
of
the
p
ump.
Slip =
Q
T

Q
act
%
Slip
= [ (
Q
T

Q
act
)
/
Q
T
]
x
100
If
Q
act
is
more
than
the
Q
T
then
slip
w
ill
be
–
iv
e.
If
Q
act
lesser
than
Q
T
then
the
slip
will
be
+ive.
6)
Define
coefficient
of
dis
c
harge
of
reciprocating
p
u
mp?
It
is
defin
e
d
as
the
ratio
of
actual
discha
r
ge
to
theoretical discharge of
reciprocati
n
g pump.
C
d
=Qa/Qth.
If
C
d
>
1
then
–
ive
slip
occurs
and
if
C
d
<
1
then
+ive
slip
occurs.
7)
Write
the
ex
pression
f
or
pressure
head
due
to
acc
e
le
r
ation in
s
u
ction
and
delivery
pipes.
Pressure
h
ead
due
to
acceleration
in suction
pipe,
h
as
=
(l
s
/g)
(
A/a
s
)
ω
2
r
C
os
ω
t
Where,
l
s

length
of
suction
pipe;
A
–
area
of
piston
cylinder,
a
s
–
area
of
suction
p
i
p
e;
ω
–
angular
velocity;
r
–
radius
of
crank.
Pressure
h
ead
due
to
acceleration
in delivery
pipe,
h
ad
=
(l
d
/g)
(A/a
d
)
ω
2
r
C
os
ω
t
Where,
l
d

length
of
delivery
pipe;
A
–
area
of
piston
cyli
nd
e
r,
a
d
–
area
of
delivery
pipe;
ω
–
angular
velocity;
r
–
radius
of
crank.
Max
press
u
re
head
due
to
acceleration,
h
a
=
(l/g)
(A/a)
ω
2
r
20
T.G.PACKIA RAJ
M.E
.
, (Ph.D),
Asst. Professor
, Depar
t
ment of
Mechanical
Engi
n
eeri
n
g,
The Rajaas
E
n
gineeri
n
g College,
Vadakkangulam
.
8)
Write
the
expression
for
head
due
to
friction
in
s
u
ction
and
d
e
livery
pipes.
Head
loss
due
to
friction
in suc
tion
pipe
is,
h
fs
=
(4fl
s
/
2
gd
s
)
[
(A/a
s
)
ω
2
r
Sin
ω
t
]
2
Where,
f
–
coefficient
of
friction;
l
s

length
of
suction
pip
e
;
A
–
area
of
piston
cylinder,
a
s
–
area
of
suction
pip
e
; d
s
–
diameter
of
suction
pipe;
ω
–
Angular
velocity;
r
–
radius
of
cr
a
nk.
Head
loss
due
to
friction
in deliv
e
r
y
pipe
is,
h
fs
=
(4fl
s
/
2
gd
s
)
[
(A/a
s
)
ω
2
r
Sin
ω
t
]
2
Where,
f
–
coeffici
e
nt
of
friction;
l
s

length
of
delivery
pipe;
a
s
–
area of
delivery
pipe;
d
s
–
diameter
of
delivery
pipe;
9)
Define
indicator
diagr
a
m?
Th
e
indica
t
or
diagram
for
a
recip
r
ocating p
u
mp
is
defi
n
ed
as
the
g
raph
drawn
between
the
pressure
h
ead
in
the
cylinder
and the
distance
traveled
by
the
piston
for
one
complete
revolution
of
the
crank.
10)
Define
ideal
indicator
di
a
gram?
It
is
defined
as
the
graph
between
pressure
head
in
the
cylinder
and
stroke
length
of
the
crank
under
ideal
con
d
ition
is
known
as
ideal
i
n
dicator
diagr
am
.
During
the
suction
str
o
ke,
the
pr
e
ssure in
t
h
e
cylinder
is
below
a
t
mospheric
pressure.
During
the
delivery
stroke,
the
pressure in
the
cylinder
is
above
a
t
mospheric
pressure.
P
r
e
s
s
u
r
e
h
H
atm
e
a
d
Delivery
s
t
r
ok
e
h
d
L = Stroke L
e
ngth
h
s
Su
c
tion
s
t
roke
Stro
k
e Leng
th
11)
What
is
t
h
e
relation
b
etween
Work
done
of
a
Pump
and
Area
of
I
ndicator
Diagra
m
?
Work
done
by
the
pump
is
proporti
o
nal
to
the
a
r
ea
of
the
In
d
icator
diagr
am
.
12)
What
is
the
Work
done
by
the
Pump
per
sec
d
ue
to
accel
e
ration
and
f
r
iction
in
the
suction
and
delivery
Pipes?
For
single
acting
:
Workdone/sec
=
ρgALN(h
s
+h
d
+0.67h
fs
+0.67h
f
d
)/60
For
Double
acting
:
Workdone/sec
=
2
ρgALN(h
s
+h
d
+0.67h
fs
+0.67h
f
d
)/60
Where,
h
f
s
,
h
f
d
=loss
of
head
due
to
friction
in
s
u
ction
and
d
e
livery
pipes.
21
T.G.PACKIA RAJ
M.E
.
, (Ph.D),
Asst. Professor
, Depar
t
ment of
Mechanical
Engi
n
eeri
n
g,
The Rajaas
E
n
gineeri
n
g College,
Vadakkangulam
.
13)
What
is
an
air
vessel?
An
air
vessel
is
a
cl
o
s
e
d
chamber
containing
compressed air
in
the
t
o
p
po
rtion
and
liquid
a
t
the
bott
o
m
of
the
c
h
amber. At
the
base
of
the
chamber
there
is
a
n
opening
thr
o
ugh
which
the
liquid
may
flow
into
the
vessel
or
o
ut
from
the
vessel.
When
the
liquid
enters
the
air
vessel,
the
air
g
ets
compressed further
and
when
the
li
quid
flows
out
of
the
vessel,
the
a
ir
will
expand
into
the
chamber.
14)
What
is
the
purpose
of
a
n
air
vessel
fitted
in
the
pump?
o
To
obtain
a
continuous
supply
of
li
q
uid
at
a
uni
f
orm
rate.
o
To
save
a
considerable
amount
of
work
in
overcoming
the
frictio
n
a
l
resistance
in
the
sucti
o
n
and
delivery
pipes,
and
o
To
run
the
pump
at
a
high
speed
wi
t
h
out
separ
a
tion.
15)
What
is
the
work
saved
by
fitting
a
n
air
vessel
in
a
single
acting,
dou
b
le
acting
pump?
Work
saved
by
fitting
ai
r
vessels in
a
single
ac
ti
ng
p
ump
is
84.87%, In
a
double
acti
n
g
pump
the
work
saved
is
39.2%.
16)
Define
Cavi
t
ation.
If
the
pressure
in
the
cylinder
is
b
e
low
the
vapour
pressu
r
e,
the
dissolved gases
will
be
libe
r
ated
from
the
liquid
and
air
bubbles
are
formed.
This
proc
e
ss
is
t
ermed
as
cavitaion.
17)
Define
sep
a
ration
pressure
and
se
p
aration
pressure
head.
Due
to
caviation
process
the
conti
n
uous flow
of
fluid
will
g
e
t
affected
a
nd
separation takes
place.
The
pressure
at
which
separation takes
place
is
known
as
separation
pressure
a
n
d
the
head
correspon
d
ing to
sep
a
ration
pressure
is
call
e
d
separation
p
ressure
he
a
d.
For
water
the
limiting
value
of
separ
a
tion
pressu
r
e
head
is,
h
sep
=

7.8
m
(Gauge
pressure)
h
sep
=
10.3
–
7.8
=
2.5
m
(Absolute
pressure)
18)
How
will
you
obtain
the
max
i
mum
s
peed
during
suction
str
o
ke?
The
absolu
t
e
pressure head
will
be
minim
u
m
a
t
the
begin
n
ing of
sucti
o
n
stroke.
Thus,
in
the
cylinder
the
separati
o
n taking
pl
a
ce
at
the
beginning of
suction
stroke
only.
In
this
case,
the
absolu
t
e
pressure
head
will
be
equal
to
the
s
e
paration
pressure.
h
sep
=
H
atm
–
(h
s
+
h
as
)
[or]
h
as
=
H
atm
–
h
s
–
h
sep
But
max
i
m
u
m
pressure
head
due
to
acceleration
in
suction
pipe
is
,
h
as
=
(l
s
/g)
(
A/a
s
)
ω
2
r
Equating
both
the
angular
velocity
(
ω)
and
Sp
e
ed
(N)
are
o
btained.
This
N
is
the
maximum
speed
of
the
pump
during
the
suction
str
o
ke
without
s
e
paration.
19)
How
will
you
obtain
the
max
i
mum
s
peed
during
delivery
stroke?
The
absolu
t
e
pressure
h
ead
will
be
minim
u
m
at the
end
of
d
elivery
stroke.
Thus,
in
t
h
e
cylinder
the
separat
ion
t
aking
pl
a
c
e at
the
end
o
f
delivery
stroke
only.
In
this
case,
t
h
e
absolute
p
ressure
he
a
d
will
be
eq
u
al
to
the
se
p
aration
pressure.
22
T.G.PACKIA RAJ
M.E
.
, (Ph.D),
Asst. Professor
, Depar
t
ment of
Mechanical
Engi
n
eeri
n
g,
The Rajaas
E
n
gineeri
n
g College,
Vadakkangulam
.
h
sep
=
H
atm
+
h
s

h
ad
[or]
h
ad
=
H
atm
+
h
d
–
h
sep
But
max
i
m
u
m
pressure
head
due
to
acceleration
in
delivery
pipe
i
s
,
h
ad
=
(l
d
/g)
(A/a
d
)
ω
2
r
Equating
both
the angular
velocity
(
ω) and
Sp
e
ed
(N) are
o
btained.
This
N
is
the
max
i
mum
s
pped
of
the
pump
during
the
delivery
stroke
wit
h
out
separation.
20)
What
is
mean
by
M
a
ximum
speed
of
a
Reciprocating
Pump?
The m
a
xim
u
m
s
peed
at
which
no
separation
fl
o
w is
taking
place
in
the
cylinder
is
called
maximum
speed
of
a
recip
r
ocating
p
u
mp.
It
will
be
the
least
value
of
speeds
ob
ta
ined
from
maxim
u
m
speed
during
suction
stroke
and
maximum
speed
during
delivery
stroke.
21)
Write
th
e
workdone
saved
by
fitting
t
he
air
vess
e
l
in
recipr
oc
ating
pump.
By fitting
the
air
vessel
t
he
head
l
o
ss
due
to fric
t
ion
in
sucti
o
n
and
delivery
pipe
is
reduced.
This
reduction in
the
head
loss
saves
a
certain
amo
u
nt
of
energy.
Therefore,
the
workdone
s
aved
is
given
by,
Workdone
saved
by
workdone
against
fric
t
ion
workdone
against
friction
Fitting
airvessel
without
a
irvessel
with
airvessel
22)
Write
the
formula
for
workdone
a
g
ainst
fric
t
ion
with
air
vessel
in
r
e
ciprocating
pump.
Workdone
agains
t
friction
w
ith
a
i
rvessel
=
[K/π]
ρ
g
Q
[
4
fl/2gd]
[(A/a)
ω
r]
2
Where,
K
=
1
for
si
n
gle
acting
r
e
ciprocating
pump
K
=
2
for
double
acting
r
eciprocating
pump
Q
=
theoretical
dischar
g
e
(m
3
/s)
Q
=
ALN/60
for
single
ac
ting
reciprocating
pump
Q
=
2ALN/
6
0
for
doubl
e
acting
reciprocating
pump
f =
coeffici
e
nt
of
friction
l =
length
of
pipe
(m)
d
=
diameter
of
pipe
(m)
A
=
area
of
piston
(m2)
a
=
area
of
pipe
(m2)
ω
=
angular
velocity
(rad/s)
ω
=
2πN/60
r
=
radius
of
crank
23)
What
will
be
the
total
%
work
saved
by
fi
tting
the
air
vessel?
For
single
a
cting
recipr
o
cating
pump
=
84.8
%
For
double
acting
reciprocating
pump
=
39.2
%
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