Streamlines, Streaklines, and Pathlines

Streamlines, Streaklines, and Pathlines

1. Streamlines

   • A set curves that are tangent to the flow velocity at an instant.
     • Blue & grey lines= streamlines. Red arrows =direction and magnitude of the flow velocity. The arrows = tangential to the streamline. Ca, C2 = Stream surfaces
   • These show the direction a fluid element will travel in at any point in time.

2. Pathlines

   • represents the path that is followed by one particle released into the fluid; the actual path traversed by a given fluid particle.
   • Also be referred to as flow lines in physics.
   • Difference between streaklines and pathlines
     • 1. Pathline for a particle released at an initial point in time.
       • 2. Pathline shows path for the second particle, released from the same point but at a later time, the pathline is different because the flow has changed.

3. Streaklines

   • The locus of points of all the fluid particles that have passed continuously through a particular spatial point in the past.
   • Dye steadily injected into the fluid at a fixed point extends along a streakline.

Images and files in the map