Transitional flow refers to a flow regime that falls between laminar flow and turbulent flow in fluid dynamics. In fluid mechanics, the behavior of a fluid (liquid or gas) is categorized into different flow regimes based on the Reynolds number, which is a dimensionless parameter that characterizes the flow patterns.
The transitional flow regime can be important in various engineering applications, such as in pipes, channels, and over surfaces. Understanding the transition from laminar to turbulent flow is needed for predicting and optimizing the performance of fluid systems. The transition is influenced by factors such as the Reynolds number, surface roughness, and the presence of disturbances in the flow.