Explain impulse
turbine?
If at the inlet of
the turbine the energy available is only kinetic energy the turbine is known as impulse turbine.
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.
Explain tangential
flow turbine.
If the water flows
along the tang
ent of the runner, the turbine is known as the tangential flow
turbine.
Explain radial flow
turbine.
If the water flows
in the radial direction through the runner the turbine I called radial flow
turbine.
Explain inward flow
radial turbine.
If the water flows
from outwards to inwards radially the turbine is called inward radial flow
turbine.
Explain outward flow
radial turbine.
If the water flows
radially from inwards to outwards the turbine is known as outward radial flow
turbine.
What is 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.
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.
Mention the general
characteristics of laminar flow.
• There is a shear stress between fluid
layers
• ‘No slip’ at the boundary
• The flow is rotational
• There is a continuous dissipation of
energy due to viscous shear
What are the factors influencing the
frictional loss in pipe flow?
Frictional
resistance for the turbulent flow is
i. Proportional to vn 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. Depend on the
nature of the surface in contact.
What is the expression for head loss due to
friction in Darcy formula?
hf = 4fLV2 / 2gD
Where,
f = Coefficient of
friction in pipe
L = Length of the
pipe
D = Diameter of pipe
V = velocity of the
fluid
What do you understand by the terms a) major
energy losses, b) minor energy losses?
Major energy losses:
-
This loss due to
friction and it is calculated by Darcy weis bach formula and chezy’s formula.
Minor energy
losses:-
This is due to
i. Sudden expansion
in pipe.
ii. Sudden contraction in pipe.
iii. Bend in pipe.
iv. Due to
obstruction in pipe .
Give an expression for loss of head due to
sudden enlargement of the pipe:
he = (V1-V2)2
/2g
Where,
he = Loss of head
due to sudden enlargement of pipe .
V1 = Velocity of
flow at section 1-1
V2 = Velocity of
flow at section 2-2
Give an expression for loss of head due to
sudden contraction:
hc =0.5 V2/2g
Where,
c = Loss of head due to sudden
contraction.
V = Velocity at outlet of pipe.
Give an expression for loss of head at the
entrance of the pipe:
hi =0.5V2/2g
Where,
hi = Loss of head at
entrance of pipe.
V = Velocity of
liquid at inlet and outlet of the pipe.
What is the terms Hydraulic
gradient line [HGL] and Total Energy line [TEL]?
Hydraulic gradient
line:
Hydraulic gradient
line is defined as the line which gives the sum of pressure head and datum head
of a flowing fluid in a pipe with respect the reference line.
Total energy line:
Total energy line is
defined as the line which gives the sum of pressure head, datum head and
kinetic head of a flowing fluid in a pipe with respect to some reference line.
What is sypon? Where
it is used?
Sypon is along bend
pipe which is used to transfer liquid from a reservoir at a higher elevation to
another reservoir at a lower level.
Uses of sypon: -
1. To carry water
from one reservoir to another reservoir separated by a hill ridge.
2. To empty a
channel not provided with any outlet sluice.
What are the basic
educations to solve the problems in flow through branched pipes?
i. Continuity equation.
ii. Bernoulli’s formula.
iii. Darcy weisbach
equation.
Name any five
parameters required to evaluate economic thickness of insulation
For determination of economic
thickness following parameters are required:
i) Cost of fuel
ii) Annual hours of operation
iii) Heat content of fuel
iv) Operating surface temperature
v) Pipe diameter / thickness of surface
vi) Estimated cost of insulation
vii) Average ambient air temperature
What
are the advantages of fluidized bed combustion over fixed grate boiler?
- The major advantages are as under:
- Burn low-grade fuels.
- Reduces NOx and SOx
- No clinker formation. Faster response to changing demand.
- Suited for fluctuating fuel quality
- Higher combustion efficiency