Define streamline flow.

A streamline is a path traced out by a massless particle as it moves with the flow. It is easiest to visualize a streamline if we move along with the body (as opposed to moving with the flow).

Streamline flow is an uninterrupted flow (as of air) past a solid body in which the direction at every point remains unchanged with the passage of time.

A streamline is a path traced out by a massless particle as it moves with the flow