We were
discussing the basics
of shear stress in turbulent flow, minor
head losses in pipe flow, hydraulic
gradient and total energy line, basic concept and working of
syphon, flow
through pipes in series, flow
through pipes in parallel, flow
through branched pipes and power transmission through pipes, in the
subject of fluid mechanics, in our recent posts.

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Now we
will go ahead to see the concept of flow through nozzle, power transmission
through nozzle, efficiency of power transmission through nozzle and we will
also find here the condition for maximum transmission of power through nozzle,
in the subject of fluid mechanics, with the help of this post.

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**What
is a nozzle? **

Nozzle is an engineering device which will
accelerate the fluid and hence fluid velocity or kinetic energy of fluid will
be increased while pressure of fluid will be reduced.

Let us see
the nozzle which is fitted at the end of a long pipe as displayed in following
figure. Total energy at the end of pipe will be summation of pressure energy
and kinetic energy. Total energy will be converted in to kinetic energy by fixing
a nozzle at the end of pipe and therefore velocity of fluid flowing through nozzle
will be increased.

Nozzles are
used to increase the velocity of flowing fluid and let us find here the few
examples of application of nozzle as mentioned below.

- In case of Pelton turbine, the nozzle is used at the end of pipe for increasing the velocity.
- In case of fire extinguisher, a nozzle is used at the end of hose pipe for increasing the velocity of flow.

Let us
consider the following data from above figure.

D =
Diameter of the pipe

L = Length
of the pipe

A = Area
of the pipe

V =
Velocity of flow in pipe

H = total
head at the inlet of the pipe

d =
Diameter of nozzle at outlet

v =
Velocity of flow at outlet of nozzle

a = Area
of the nozzle at the outlet

f =
Co-efficient of friction for pipe

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**Velocity of flow at the outlet of
nozzle**

Velocity of flow at the outlet of nozzle will be given by following
formula as mentioned here

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**Discharge through the nozzle **

Discharge through nozzle will be given by following formula as mentioned here

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**Power transmission through nozzle**

Power transmitted through nozzle will be given by following formula as
mentioned here

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**Efficiency of power transmission through nozzle**

Efficiency
of power transmission through nozzle will be determined with the help of
following formula as mentioned here.

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**Condition for maximum transmission of power through nozzle **** **

Above
expression is the condition of maximum transmission of power through nozzle. We
can conclude from above equation that power transmitted through a nozzle will
be maximum when the head loss due to friction will be one-third of the total
head at inlet of the pipe.

**Diameter of nozzle for maximum transmission of power through nozzle**

Diameter of nozzle for maximum transmission of power

**through nozzle will be given by following formula as mentioned here.**
Further we
will go ahead to find out the concept of water hammer in the pipes

**,**in the subject of fluid mechanics, with the help of our next post.
Do you
have any suggestions? Please write in comment box.

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**Reference: **

Fluid
mechanics, By R. K. Bansal

Image
courtesy: Google