Secondary flow

Secondary flow refers to the flow patterns that occur in a fluid dynamics context, particularly in situations where the primary flow direction is established by external forces or conditions, such as pressure gradients or gravity. This concept is commonly discussed in the contexts of: 1. **Turbulence**: Secondary flows often arise in turbulent conditions, where the fluid exhibits complex and chaotic motion. These flows can include vortices and other rotational motions that are perpendicular to the main flow direction.