What is a streakline?

Answer 1

Streak line is the path that includes all particles in the flow at any specific time t.

Answer 2

A streakline is a path that a fluid element follows in a flow field, showing the history of that element's movement over time. It is visualized by tracking a dye or particle injected into the flow and observing its trajectory. Streaklines can help visualize fluid flow patterns and understand how elements move within a flow.