Characterisation of inexpensive, simply shaped nozzles

The paper introduces a simple model for description of steady-state characteristics (loss dependence on Reynolds number) of the simplest nozzles, the shapes of which - with sharp edges - lead to separation of flow from the wall at the entrance into the exit channel and formation of a separation bubble. In particular, the appropriateness of the characterisation was tested on nozzles with 90° and 45° sharp-edge entrance.