civil - Applied Hydraulic Engineering
1.What do you
mean by turbine?
The hydraulic machine which convert the hydraulic
energy in to mechanical energy is called turbine
2.Define pump :
It is defined as the hydraulic machine which convert
mechanical energy in to hydraulic energy
3.Define sub
critical flow:
If the froude
number is less than one then the flow is said to be sub critical flow
4.Define
critical flow:
If the froude
number is less equal to one it is called as critical flow.
5.Define
supercritical flow:
If the froude
number is greater than one it is called as super critical
flow
6. What are the possible types of flow in open
channel with respect to space and time? A,steady and unsteady flow
B,uniform and
nonuniform flow
7.what do you
know about uniform and non uniform flow?
Uniform flow: If
the given length of the channel ,depth ,velocity ,the rate of flow, cross
section are
constant.
Non
Uniform flow: If the given length of the channel ,depth ,velocity ,the rate of
flow, cross section are not constant.
8.Define
specific energy:
It is defined as energy per unit weight of the
liquid with respect to the bottom of the channel.
9.What is meant
by wetted perimeter?
The wetted perimeter (p) is the length of the line
of intersection of the channel wetted surface with the cross section plan
normal to the direction of flow.
10.Define
critical depth:
It
is defined as the depth of flow of water at which the specific energy is
minimum.
11.Define
critical velocity:
The velocity of
flow at the critical depth is known as critical velocity.
12.Define the
term most economical section of the channel:
A section of the channel is said to be most
economical when the cost of construction of the channel is minimum. But the
cost of construction depend up on the excavation and lining to keep the cost
minimum The wetted perimeter for a given discharge should be minimum.
13.Define
gradually varying flow
If the change in
depth in a varying flow is gradual so that the curvature of the
streaming line
is not excessive such flow is called gradually varying flow.
14.Define
Rapidly varying flow
If the curvature
in a varied flow is large and depth changes appreciably over
short length it
is called rapidly varying flow.
15.Define affux
The maximum
increase in water level due to obstruction in the path of flow is
known as affux.
15.Define length
of backwater curve
The distance
along the bed of the channel between the section where water starts raising to
the section
where water is having maximum height is known as the length of the back water
curve
16.Define back
water
The profile of
the raising water on the upstream side of the dam is called as back water curve.
17.Define
hydraulic jump
The
raise of water level which takes place
due to the transformation of the unstable shooting flow
( super critical flow ) to the stable
Streaming flow ( sub critical
flow ) is called hydraulic jump.
18.Define cavitations
cavitations is defined as phenomenon of formation of
vapour bubbles in a region of a flowing liquid where the pressure in the liquid
is falls below than vapour pressure and sudden collapsing of these vapour
bubbles in a region of higher pressure.
19.What is known
by governing of a turbine?
Governing of a turbine is defined as the operation by
which the speed of the turbine is
kept constant
under all conditions of working . It is done by oilpressure generator.
20.Explain gross
head
The
difference between head race level and tail race level when no water is flowing
is know as gross head 21.Explain net head
It
is defined as the head available at the inlet of turbine .If Hf is the loss due
to friction between water and penstock then net head
H=Hg-Hf
22.Define
Hydraulic Efficiency:
It is defined as the ratio of power
delivered to the runner to the power supplied at the inlet.
23.Define
mechanical efficiency
It is defined as the ratio of power at
the shaft of the turbine to the power delivered by the water to runner.
24.Define
volumetric efficiency
It is defined as the ratio of volume
of water actually striking the runner to the Volume of water supplied to the
runner.
25.Define
over all efficiency
It is defined as the ratio of shaft
power by water power
26.Explain
impulse turbine
If at the inlet of the turbine the
energy available is only kinetic energy the
turbine is known as impulse turbine.
27.Explain
Reaction turbine
if at the inlet of the turbine the
water possesses kinetic energy as well as pressure energy the turbine is known
as reaction turbine.
28.Explian
tangential flow turbine
If the water flows along the tangent
of the runner, the turbine is known as the tangential flow turbine.
29.Expain
radial flow turbine
If the water flows in the radial
direction through the runner the turbine I called radial flow turbine.
30.Explain
inward flow radial turbine
If the water flows from outwards to
inwards radially the turbine is called iward radial flow turbine.
31.Explain
outward flow radial turbine
If the water flows radially from inwards to outwards
the turbine is known sa outward radial flow turbine.
32.Define axial
flow turbine
If the water flows through the runner along the
direction parallel to the axis of rotation of the runner the turbine is called
axial flow turbine.
33.what is
Pelton wheel:
Pelton wheel or Pelton turbine is a tangential flow
impulse turbine. The water strikes the bucket along the tangent of the runner .
The energy available at the inlet of the Turbine is only kinetic energy.This
turbine is used for high heads.
34.What is
breaking jet?
When the nozzle is completely closed ,the amount of
water striking the runner reduces to zero but the runner due to inertia goes on
revolving
for a long time
to stop the runner in a short time a small nozzle is
provided
which direct the jet of water on the back of vanes .This jet of water is called
breaking jet.
35.What is jet
ratio?
It is the ratio
of pitch diameter (D) to the diameter of jet (d).
36.What is Draft
tube?
A tube or pipe of gradually increasing area is used
for discharging water from the exit of the tubine to the tail race is called
draft tube.
37.Define Degree
of Reaction (R)
It is defined as the ratio of change of pressure
energy inside the runner to the change of total energy out side the runner.
38.what is
radial discharge?
This means the angle made by absolute velocity with
the tangent on the wheel is 90 and the component of whirl velocity is zero.
39.Define
Francis turbine:
Inward
flow reaction turbine having radial discharge at outlet is known as francis turbine
40.Define
propeller turbine:
This
is an example of axial flow reaction turbine . Here the vanes are fixed to the
hub and are not adjustable.
41.Define
Kaplan turbine:
This
is an example of axial flow reaction turbine. Here the vanes are not fixed to
the hub and are adjustable.
42.What
are the use of draft tube?
1.the
net head on the turbine increases.
2.due
to increase in net head the power and efficiency of the turbine also increases.
3.the
large amount of rejected kinetic energy is converted in to usefull pressure
energy
43.What
are types of draft tube?
1.conical
draft tube
2.simple
elbow tube
3.moody
spreading tube
3.draft
tube with circular inlet and rectangular outlet.
44.What
are the types of characteristic curves
1.Main
characteristic curves
2.Operating
characteristic curve
3.Muschel
characteristic curves
45.What
is specific speed of the turbine?
It
is defined as the speed of a turbine which will develop unit power under unit
head.
46.Define
unit quantities;
Unit
quantities are the quantities which are obtained when the head on the turbine
are unity.
47.Explain
about characteristic curves of a hydraulic turbine
Characteristic
curves of a hydraulic turbine are the curves with the help of which the exact
behaviour and performance of the turbine under different working conditions can
be known.
48.What
is meant by conveyance of the channel?
The
conveyance of the channel is denoted by k and is given by k=AC?(m)
49.Define
the term most economical section:
A
section of the channel is said to be most economical when the cost of
construction of the channel is minimum. But the cost of construction mainly
depend up on the excavation and lining to keep the cost minimum ,the wetted
perimeter for a given discharge should be minimum.
50.What
are the conditions of rectangular channel of best section?
The
two conditions are breadth is equal to two times the depth (b=2d) and hydraulic
mean depth is equal to half the depth
(m=d/2)