Flow through a venturi

Flow through a Venturi V015-1

In another paper I gave you the formula for computing the approximate flow through an orifice or nozzle. Here is the formula for an approximate flow through a venturi tube

For any venturi tube use:

Or you can use:

Q = flow, in gpm

d1= diameter of venturi throat in inches

d2 = diameter of main pipe in inches

H = difference in head between upstream end and throat.

These formulas will work for any liquid with a viscosity similar to water.

  • The values given here are for water.
  • 32.174 feet/ second/ second was used for the acceleration of gravity
  • 7.48 gallons/ cubic foot was used to compute the constants