Abstract
In order to study the form ation of the hydraulic jump, several numerical experiments are conducted about the three-dimensional flow of two layers over an isolated obstacle. As a clue to under-, standing the results of the numerical experiment, the criterion for the existence of a steady flow over an obstacle is considered using the two-dimensional flow in linearized formulation.
The results of six out of eight nume r i cal experiments performed in the present study are examined: three cases do exist in the steady regime, the other three in the unsteady regime. In the cases of the steady regime the continuous flow is obtained throughout the whole region, but in the cases of the unsteady regime a bow-shaped jump appears in the leeside of the obstacle, as is observed in the single fluid system. In the steady cases the internal surface tends to change more remarkably than the external surface; in the unsteady cases a reverse tendency holds.
