Practical applications of Bernoulli’s equation:

 Practical applications of Bernoulli’s equation: 

 Although Bernoulli’s equation is applicable in all problems of incompressible flow where there is involvement of energy considerations. But we shall consider its application to the following measuring devices.

 1) Venturimeter 

 2) Orifice meter 

 3) Pitot tube 

Differential Pressure 

Flow Meters Differential pressure flow meters all infer the flow rate from a pressure drop across a restriction in the pipe. For many years, they were the only reliable methods available, and they remain popular despite the development of higher performance modern devices, mostly on account of exceptionally well researched and documented standards. 

The analysis of the flow through a restriction (Fig.1) begins with assuming straight, parallel stream lines at cross sections 1 and 2, and the absence of energy losses along the streamline from point 1 to point 2. 

 The objective is to measure the mass flow rate, 

m . By eqn. continuity m . = ρv1a1 = ρv2a2. 

Bernoulli’s equation may now be applied to a streamline down the centre of the pipe from a point 1 well upstream of the restriction to point 2 in the vena contracta of the jet immediately downstream of the restriction where the streamlines are parallel and the pressure across the duct may therefore be taken to be uniform: