What is Venturimeter?
Main parts of Venturimeter
- A short converging part: It is that portion of the venturi where the fluid gets converges.
- Throat: It is the portion that lies in between the converging and diverging part of the venturi. The cross section of the throat is much less than the cross section of the converging and diverging parts. As the fluid enters in the throat, its velocity increases and pressure decreases.
- Diverging part: It is the portion of the venturimeter (venturi) where the fluid gets diverges.
Principle of Venturimeter
The working of venturimeter is based on the principle of Bernoulli’s equation.
- Short converging part: It is a tapered portion whose radius decreases as we move forward.
- Throat: It is middle portion of the venturi. Here the velocity of the fluid increases and pressure decreases. It possesses the least cross section area.
- Diverging part: In this portion the fluid diverges.
- Here we have considered two cross section, first at the inlet and the second one is at the throat. The difference in the pressure heads of these two sections is used to calculate the rate of flow through venturimeter.
- As the water enters at the inlet section i.e. in the converging part it converges and reaches to the throat.
- The throat has the uniform cross section area and least cross section area in the venturimeter. As the water enters in the throat its velocity gets increases and due to increase in the velocity the pressure drops to the minimum.
- Now there is a pressure difference of the fluid at the two sections. At the section 1(i.e. at the inlet) the pressure of the fluid is maximum and the velocity is minimum. And at the section 2 (at the throat) the velocity of the fluid is maximum and the pressure is minimum.
- The pressure difference at the two section can be seen in the manometer attached at both the section.
- This pressure difference is used to calculate the rate flow of a fluid flowing through a pipe.