We were discussing the basic difference between orifice and mouthpiececlassification of orifices and mouthpiecesadvantages and disadvantages of orificeshydraulic coefficientsexperimental process to determine the hydraulic coefficientsflow through fully submerged orificeflow through partially submerged orifice and also time of emptying a tank through an orifice fitted at its bottom in the subject of fluid mechanics in our recent posts.

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 with the help of this post.

Let us consider we have one hemispherical tank filled with a liquid up to a height of H1. Let us consider that one orifice is fixed at the bottom of the hemispherical tank. We are interested here to determine the time taken in emptying the hemispherical tank.
Let us consider the following data from above figure.
R = Radius of the hemispherical tank
A = Area of the tank
a = Area of the orifice
H1= Initial height of the liquid in the hemispherical tank
H2= Final height of the liquid in the hemispherical tank
T = Time taken in emptying the tank from Hto H2

Time taken in emptying the hemispherical tank from Hto H2 will be given by following formula as mentioned here.

Let us determine the time emptying the tank, Hwill be zero.

This is the expression for the time emptying the hemispherical tank fitted with orifice at its bottom.

Now we will go ahead to find out the method to determine the time of emptying a circular horizontal 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