Flow Separation At the Initial Stage of Oblique Water Impact of Wedge Shaped Bodies
The initial parameters corresponding to flow separation from the wedge vertex during the initial stage of the impact of a wedge on a liquid halfspace are studied. The liquid is assumed to be ideal and incompressible; gravity and surface tension effects are ignored. The analytical solution of the problem is found in terms complex variables by constructing the flow potential in a parameter region. The expression for the flow potential is obtained using generalized integral formulae for solving mixed and uniform boundary value problems for the first quadrant. It includes two unknown functions, which are the velocity magnitude and angle to the free surface determined from the dynamic and kinematic boundary conditions. The analysis of the computations revealed the limit combination of the initial parameters at which the pressure along the whole length of one side of the wedge becomes less than the atmospheric pressure. Such a pressure distribution results in the ventilation of the wedge side, which starts from the contact point on the free surface and extends suddenly along the whole length of the wedge side, thus leading to flow separation from the wedge vertex.