A stream with an initially undisturbed free surface is set impulsively in motion and a (small) pressure perturbation is applied to the surface. The form of the free surface as a function of time is examined in detail up to the point where the disturbance is sensibly that of a steady-state lee wave.
Wurtele, M. G.. 1955. "The transient development of a lee wave." Journal of Marine Research 14, (1). https://elischolar.library.yale.edu/journal_of_marine_research/820