Keiji Murata

The intrusion of the interflow into the various density profile environments

Yusuke Fukushima

An experimental study is carried out on the density interflow which flows into a place where the density exists.The density interflow is generated by the density differences between the upper, lower and intrusion water. An example of the interflow is the motion of a turbid interflow into the stratified reservoir where the density of the lower layer is larger than that of the inflow water.
In this study, the flow characteristics of the intrusion phenomena are investigated. The densities of the ambient water and the inflow water are changed in the experiments.The results of experiments show that the travel speed of the front is small and the maximum thickness of the interflow water is large when the relative density difference between the inflow water and the upper water is small.
The front of the interflow intrudes to form a wedge when the density of the ambient water smoothly changes. The front of the interflow forms a typical shape when the density of the ambient water changes discontinuously.The travel speed obtained from the experiments is compared with that expressed in the equations of Manins and Kao.The experimental results of the travel speed are larger than the theoretical ones.The reason for this result is that the following factors are neglected in the theoretical treatment, i.e. the drag force of the front which acts on the inflow water, the frictional resistance at the interfaces, the mixing of the ambient water, and the inverse flow.Taking these factors into consideration, the theory explains the experimental results well.