An error analysis of streaklines as curves

A streakline is a visible curve consisting of fluid particles which emerged continuously from a fixed point in a given flow field. In many cases we do not know the exact velocity field but can get an approximate velocity fiel d. The computation of streaklines includes the discretization error as well as the error caused by the approximate velocity field. We give an error an alysis of streaklines as curves in terms of tau and h, discretization param eters of the streakline and of the velocity field. We show that, when the v elocity field is approximated piecewise linearly, a computation scheme base d on the Heun method is the best choice to approximate streaklines from the viewpoint of accuracy and efficiency. We present simulation results of str eaklines emerging from the surface of a circular cylinder at Reynolds numbe rs 100 and 10000.