Turbulent Flow over a Backward-Facing Step

Application ID: 228

The backward facing step is an interesting case for studying the performance and solution strategy of a turbulence model. In this case, the flow is subjected to a sudden increase of cross-sectional area, resulting in a separation of flow starting at the point of expansion.

Spatial variations in the velocity field cause production of turbulence outside the wall region and its interaction with the mean flow influences the size of the separation bubble. The size of the bubble, or the re-attachment length, is one of the quantities that must be predicted accurately by a turbulence model.

This model example illustrates applications of this type that would nominally be built using the following products: