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civil - Applied Hydraulic Engineering

51.Write
down the conditions for the most economical trapezoidal channel?

1.Half
the top width is equal to one of sloping side (b+2 nd)/2=d?(1+n2)

2.Hydraulic
mean depth is equal to half the depth.

52.Write
down the conditions of most economical circular channel with maximum velocity?

?=128�45�

d=0.81D

m=0.3D

53.What
do you mean by open channel flow?

1.Open
channel flow has a free surface which is subjected to atmospheric pressure.

2.In
open channel flow the cross section is irregular.

54.What
do you mean by pipe flow?

1.Pipe
flow has no free surface and subjected to hydraulic pressure only.

2.The
cross section of the flow is fixed

55.List
the instrument used to measure open channel flow

1.pitot
tube

2.ultrasonic
flow instrument.

3.Dropper
instrument

4.Gurley
instrument.

56.What
is the best side slope for trapezoidal channel ?

?=60�
is the best side slope for trapezoidal channel.

57.what
do mean by M1 profile?

The
most common of all gradually varying flow is of M1 type which is a sub critical
flow condition obstructions to flow such as wiers, dams etc�which produce M1
profile.

58.What
are the types of flow profile? Mild slope profile

Steep
slope profile Critical slope profile Horizontal bed profile Adverse slope
profile

59.What
do you mean by M2 profile?

The
M2 profile occurs at a sudden drop in the bed of the channel in to the ponds or
pools or lakes.

60.What
do mean by M3 profile?

The
M3 profile occurs the flow yielding from a spillway or a sluice gate. 61.What
is speed ratio?

U1=??(2gH)

Where
U1 � tangential velocity of wheel at inlet

?
-speed ratio

H
� Head of the turbine.

62.What
do you mean by coefficient of velocity?

V1=Cv
(2gH)

V1
= velocity of jet

Cv = coefficient of velocity

H
= head of the turbine.

63.What
are the main parts of pelton wheel turbine?

1. nozzle and flow regulating arrangement

2. runner with buckets

3. casing

4. breaking jet

64.What
are the main mechanism of Radial flow reaction turbine?

1.casing

2.guide
mechanism

3.runner

4.draft
tube

65.Define
Multistage pump:

If
centrifugal pump consists of two or more impellers the pump is called multistage
pump. To produce a high head impellers are connected

in
series .To produce high discharge impellers are connected in parallel.

66.Define
Manometric head:

Manometric
head is the head against which a centrifugal pump has to work.

Hm
= H_{s} +h_{d} +H_{fs} +H_{fd} + (vd^{2}/2g)

�
manometric head

Hs
- suction head

Hd
� delivery head

Hfs
� friction head loss in suction pipe

Hfd
� friction head loss in delivery pipe

67.What
is Net Positive Suction Head (NPSH) ?

NPSH
is defined as the total head required to make liquid flow through suction pipe
to pipe impeller.

68.Define
slip of a reciprocating pump and negative slip:

Slip
is defined as the difference between theoretical discharge and actual
discharge. If actual discharge is greater than theoretical discharge negative
value is found this negative value is called negative slip.

69.What
do you know coefficient of discharge?

It
is defined as the ratio of actual discharge by theoretical discharge. It is
denoted By Cd.

70.What
do you know Drop down curve?

The
water surface has a convex profile upwards this curve is called drop down
curve.

71.What
is separation of reciprocating pump?

If
the pressure in the cylinder is below the vapour pressure , dissolved gasses
will be liberated from the liquid and cavitations will takes place . The
continuous flow of liquid will not exit which means separation of liquid takes
place. The pressure at which separation takes place is called separation
pressure and head corresponding to the separation pressure is called separation
pressure head.

72.What
is an indicator diagram?

Indicator
diagram is the graph between the pressure head and distance traveled by the
piston from inner dead center for one complete revolution.

73.What
is Air vessel?

Air
vessel is a closed chamber containing compressed air in the top portion and
liquid at the bottom of the chamber . It is used to obtain a continuous supply
of water at uniform rate to save a considerable amount of work and to run the
pump at high speed with out separation.

74.What
are the assumptions of gradually varying flow profile?

1.Pressure
distribution at any section is assumed to be hydrostatic.

2.The
velocity distribution at the channel section is fixed

3.The
channel is prismatic

4.The
roughness coefficient is independent of the depth of flow.

75.What
the two cases where distance of the normal depth of flow does not exit?

(a)When
the channel bed is horizontal

(b)
When the channel bed has a adverse slope.

76.What
are the methods used for finding gradually varying flow profile?

1.Direct
integration method

2.Numerical
method

3.Graphical
representation method.

77.What
are the classification of hydraulic turbine according to the type of energy at
inlet ?

(a)Impulse
turbine and

(b
Reaction turbine

78.What
are the types of turbine according to direction of flow through runner?

(a)Tangential
flow turbine

(b) Radial flow turbine

(c)Axial
flow turbine

(d) Mi
ed flow turbine

79.What
are the types of turbine according to the head at the inlet of the turbine?

(a)high
head turbine

(b)
medium head turbine

(c)low
head turbine

80.What
are the types of turbine according to the specific speed of the turbine?

(a)Low
specific speed turbine

(b)
Medium specific speed turbine

(c)High
specific speed turbine.

81.Write
down the expression for energy loss due to hydraulic jump?

HL =
(d2-d1)^{3} / (4d1d_{2})

Where

HL
� energy loss due to hydraulic jump D2 - depth of flow after the jump

D1
-- depth of flow before the jump 82.What do you mean by length of hydraulic jump?

This
is defined as the length between the two sections where one section is taken
before the hydraulic jump and the second section is taken immediately after the
jump.

83.What
are the classification of flow in channels?

1.steady
flow and un steady flow.

2.uniform
flow and non uniform flow.

3.Laminar
flow and turbulent flow and

4.sub
critical , critical and super critical flow.

84.What
are the types of Non uniform flow?

(i) Rapidly Varied Flow (R.V.F)

(ii) Gradually Varied Flow (G.V.F)

85.What
do you know about laminar and turbulent flow?

Laminar
flow: The flow in open channel is said to be laminar if the Reynolds number(
Re) is less than 500

Turbulent
flow: If the Reynolds number is greater than 2000 it is called turbulent flow.

86.What
do you mean by specific energy curve?

It
is defined as the curve which shows the variation of specific energy with
respect to depth of flow.

87.Write
the manometric efficiency of the pump?

Manometric
efficiency = (gHm)/(Vw2U2)

Where

Hm
�manometric head

88.Write
the expression for over all efficiency ? over all efficiency

=
(?g QHm)/(1000 x P) Where

Hm
� manometric head

P - power

89.What
is the minimum speed for starting the centrifugal pump?

N=(120
?manVw^{2} D)/(?(D2^{2}-D1^{2}) Where

?man
� manometric efficiency

Vw^{2}
_- Whirl at out let of the turbine D2 - diameter of impeller at out let

90.
Write down the use of centrifugal pump?

1.Used
in deep sump and basement

2.The
high discharge capacity

3.It
is driven by electric motors

Tags : civil - Applied Hydraulic Engineering

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