Oscillatory flow refers to a type of fluid movement where the flow direction and velocity change periodically over time. This can occur in various systems, such as in pipes carrying liquids or in ocean currents. The flow can be influenced by factors like pressure changes, temperature variations, or external forces. In oscillatory flow, the fluid may move back and forth, creating a repetitive pattern. This behavior is often observed in waves on the surface of water or in pumps that operate in a cyclical manner. Understanding oscillatory flow is important in fields like engineering and environmental science.