Venturi effect model

This 3D printing model allows to explain the Venturi effect. 

The Venturi effect is the reduction in the pressure as a result of an increase of a moving fluid as it flows through a constricted section of a pipe. The Venturi effect is named after its discoverer, the 18th-century Italian physicist Giovanni Battista Venturi. [1]

This effect can be explained by Bernoully's principle (a key concept in fluid dynamics), which relates the pressure, density, speed and height. Bernoully's equation can only be used for incompressible fluids. The Bernoulli equation in its standard form is:

where v is the fluid flow, g is the gravity, z is the elevation point, p is the pressure, and rho is the density. 

This experiment shows that due to a decrease in the section, there is an increase in the speed. Considering a constant elevation point, there will be a decrease in pressure in the narrow conduct. This generates a depresation enough to raise a fluid in the third tube.

In specific, in this case, we can blow in one of the broader tubes, and the other wide tube will be the output. The third narrow tube can be placed in a liquid. If we start to blow (quite strong), we will decrease the pressure in the middle point, obtaining some water in the output. If the experiment is printed with a translucid material (which, sadly, I do not have) and you use some colour liquid, you will be able to see how it reises when you blow in the input. This is the same principal use in engine's carburettors. 

The printing is really easy; I do not recommend adding internal support. It is better to go slow printing. 

[1] Venturi effect Wikipedia, Online: https://en.wikipedia.org/wiki/Venturi_effect