We were
discussing the basic difference
between orifice and mouthpiece, classification
of orifices and mouthpieces, advantages
and disadvantages of orifices, hydraulic
coefficients, experimental
process to determine the hydraulic coefficients, flow through fully submerged orifice and also flow through partially submerged orifice, in the
subject of fluid mechanics, in our recent posts.

Now we
will go ahead to find out the time of emptying a tank through an orifice fitted
at its bottom, in the subject of fluid mechanics, with the help of this
post.

Let us
consider we have one tank filled with a liquid up to a height of H

_{1}. Let us consider that one orifice is fixed at the bottom of the tank. We are interested here to determine the time taken in emptying the tank.
Let us
consider the following data from above figure.

A = Area
of the tank

a = Area
of the orifice

H

_{1}= Initial height of the liquid in the tank
H

_{2}= Final height of the liquid in the tank
T = Time taken
in emptying the tank from H

_{1 }to H_{2}.
Time taken
in emptying the tank from H

_{1 }to H_{2}will be given by following formula as mentioned here.
Let us
determine the time emptying the tank, H

_{2 }will be zero.
This is
the expression for the time emptying the tank fitted with orifice at its bottom.

Now we
will go ahead to find out the method to determine the time of emptying a hemispherical tank through an orifice at its bottom, in the subject of fluid mechanics, in
our next post.

Do you
have any suggestions? Please write in comment box.

###
**Reference:**

Fluid
mechanics, By R. K. Bansal

Image
Courtesy: Google