Question

What is the use of a contraction as flow measuring devices?

Answer 1

Flow meters are generally provided with contractions.They create differential pressure by converting potential energy of the flow into kinetic energy by changing the cross sectional area.The difference in pressure between two sections is related to the flow rate.The differential pressure is measured with a manometer between the contracted section(dowwnstream) and upstream section.These contractions are use in devices such as venturimeter,orifice meters etc to measure the flow rate.

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