Unsteady Laminar Boundary Layer on an Axisymmetric Body Subject to SmallAmplitude Fluctuations in the Free-Stream Velocity

摘要

The effect of small amplitude, time-periodic, freestream disturbances on anotherwise steady axisymmetric boundary layer on a circular cylinder is considered. Numerical solutions of the problem are presented, and an asymptotic solution, valid far downstream along the axis of the cylinder is detailed. Particular emphasis is placed on the unsteady eigensolutions that occur far downstream, which turn out to be very different from the analogous planar eigensolutions. These axisymmetric eigensolutions are computed numerically and also are described by asymptotic analyses valid for low and high frequencies of oscillation.