This simulation models compressible flow of air through a reversible nozzle/diffuser. The inlet pressure P₁, the exit velocity u₂, and the exit temperature T₂ are calculated from mass and energy balances and that the entropy change is zero. The air exits as a free jet at atmospheric pressure (P₂ = 101.3 kPa). Set the outlet diameter d₂ and inlet velocity u₁ with the sliders. When d₂ < d₁, the device acts as a nozzle, with the inlet pressure higher than the exit pressure (P₁ > P₂) in order to provide the energy needed to accelerate the air through the nozzle. When d₂ > d₁, the device operates as a diffuser, and the exit pressure is higher than the inlet pressure (P₁ < P₂). When “plots” is selected, the outlet velocity or outlet temperature is plotted as a function of outlet diameter for compressible air flow (blue) and incompressible air flow (green). Air is assumed to behave as an ideal gas and all flow is subsonic.

Download this simulation

This simulation runs on desktop using the free Wolfram Player. Download the Wolfram Player here.

About:

This simulation was made at the University of Colorado Boulder, Department of Chemical and Biological Engineering.  Author: Rachael L. Baumann

View the source code for this simulation