A numerical study on the unsteady evolution of weak axisymmetric fountain flows in a homogeneous ambient

Weak axisymmetrical fountains resulting from the injection of a dense fluid upwards into a large container of homogeneous fluid of lower density has been studied numerically in this paper using a time-accurate finite volume scheme. The behaviour of fountains for both the uniform and parabolic profiles of the discharge velocity at the fountain source has been investigated. The evolution of transient fountain flow has been analysed and two distinct stages of evolution have been identified. The time trace of the position of the fountain front has been presented and the initial, temporary and final fountain height and fountain width have been determined. The project is jointly supported by the National Natural Science Foundation of China, the Special Fund for the Young and Middle-aged Academic and Technical Leaders Training Scheme of Yunnan Province, and the Australian Development Cooperation Scholarship to Prof. Lin Wenxian. Author for correspondence: Li Yuncang.