Title: Open System Example

Open System Example: Nozzles and Diffusers

Nozzles and diffusers are devices that are used to change the velocity of the passing fluid through a change of cross-sectional area.

They are used in a variety of gadgets including garden hoses, hair dryers, jet engines and space crafts.

In this example, we will examine air flow through a diffuser.

Given the following diffuser, calculate the mass flow rate through the diffuser.

The following assumptions can be made:

(i) This is a steady-flow process

Fill in the blanks (round to one decimal place for the calculation).

Q: The mass flow rate through the diffuser is [...] kg/s.

The velocity of the air should [...] the initial velocity at the inlet. This kinetic energy is converted to internal energy that raises the temperature of the air passing through the diffuser.
A: 49.2; decrease/lower/be less than