Critical Froude number for transition from a steady to an unsteady fountain injected into a homogeneous fluid

Abstract

In this paper, we present the critical Froude number for unsteadiness at full development of plane fountains. Numerical investigations are conducted over the range of Reynolds number, 6 <= Re <= 120. The critical Froude number for transition from a steady to unsteady flow varies with the Reynolds number. For Re >= 60, the transition is independent of Re and is nearly constant at a Froude number of Fr ~ 1.0. Over the range 6 < Re <= 50, there is a significant increase in the transition Froude number.