# Venturi meter to find speed and volume of gas

A venturi meter is a device for measuring the speed of a fluid within a pipe. The drawing shows a gas flowing at a speed v2 through a horizontal section of pipe whose cross-sectional area A2 = 0.0600 m2. The gas has a density of ρ = 1.80 kg/m3. The Venturi meter has a cross-sectional area of A1 = 0.0300 m2 and has been substituted for a section of the larger pipe. The pressure difference between the sections is P2 - P1 = 150 Pa.

(a) Find the speed v2 of the gas in the larger original pipe.

m/s

(b) Find the volume flow rate Q of the gas.

m3/s

https://brainmass.com/physics/energy/venturi-meter-find-speed-volume-gas-255505

#### Solution Preview

Basic theory

Continuity equation : Assuming the liquid to be incompressible, rate of flow of liquid (that is volume of liquid flowing per sec) at any cross section is same. If the velocity of the liquid at any cross section is v, the liquid will move forward by a distance equal to v in 1 second at that cross section and area of cross section x velocity gives the volume of liquid flowing per sec. at that cross section.

Thus, as per the continuity principle, av = constant (a1v1 = a2v2 = a3v3 etc.) where a = area of cross section, v = velocity of liquid at that cross section. ........(1)

Bernoulli's theorem : For streamline flow of a perfect liquid in a pipe*, the sum of pressure energy, potential ...

#### Solution Summary

The expert uses a Venturi meter to find speed and volume of gas. A step by step solution provided.