Which type of nozzle does not include a diverging section?

A flow nozzle is designed primarily for the purpose of measuring flow rate, and it essentially consists of a converging section that accelerates the fluid, followed by a uniform section that maintains that velocity without any diverging section. This design allows for accurate measurement of flow by creating a pressure drop that can be utilized in conjunction with Bernoulli's principle.

In contrast, the Venturi nozzle features both a converging and a diverging section to facilitate the change in fluid velocity and pressure. The diverging section allows for recovery of pressure as the flow exits the nozzle. Similarly, a diffuser nozzle incorporates a diverging section that helps slow down the fluid while converting kinetic energy to pressure energy.

The converging nozzle, while not having a diverging section, serves a slightly different function, focusing even more exclusively on accelerating the fluid rather than managing flow measurement. Thus, the unique characteristic of the flow nozzle is that it maintains a constant diameter after the converging section, distinguishing it from other types that incorporate diverging sections.