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Free Surface & Bi-Phasic flows

In physics, a free surface is the surface of a fluid that is subject to constant perpendicular normal stress and zero parallel shear stress, such as the boundary between two homogenous fluids.

Applications involving free surface flows are numerous in the naval industry in order to solve issues such as sloshing, wave impact or studying the impact of hulls against water. The free surface feature also covers a wide range of engineering applications such as the dam breaking, the erosion of offshore petrol station pillars or the mixing of two fluids of different physical properties.

Two phase flow phenomena occur in various industrial applications within all fluid mechanics application fields. Aerospace, automotive, nuclear applications, etc. In all these domains, it is important to predict two phase behavior. Prediction of liquid spray in an internal combustion engine allows for better control of the combustion process and helps to curtail pollutant emissions. Another important examples include mixing of fluids, steam equilibrium within a collar system etc.

The sloshing phenomenon is of great practical importance to the safety of the liquid transport and is probably one of the most classical examples of free surface analysis. It consists in a fluid with a free surface in a partially filled tank that is given an initial slope so as to trigger its periodic oscillating under the influence of gravity (Read more).

Dam break waves have been responsible for numerous accidents making them a challenging field of research for numerical simulations. The Dam break test case is a classic validation problem for simulations involving free surfaces and consists in reproducing the collpase of a column of water under the influence of gravity and to study its propagation (Read more).

The slamming effect occurs during impact between a blunt body and the water thus generating high pressure loads. It is therefore of one the great issues that have to be addressed by the research community in Naval shipbuilding. The benchmarking test case consists in a wedge slowly entering the water at a constant velocity (Read more).

This validation test case is very similar to the previous one and consists of a cylinder impacting the water at a constant velocity. However, for this validation test case, the results will be compared to experimental ones (Read more).

This validation test case also consists of a wedge entering the water. However, this time, the wedge will be considered in free fall and the reaction of the water on the cylinder's initial velocity will be studied thus resulting in a complex fluid structure interaction problem (Read more).
For this slamming validation test case, the entering body will have a complex shape resulting in the necessity to build a 3D model. The wedge-cone specimen will enter the water at a constant velocity and results of the impact force will be compared to the experiment (Read more).
This verification test case will use the non-inertial reference frame feature. It features a rotating rigid cylinder with inside liquid and free surface. Depending on the fluid's angular velocity, the free surface will adopt a parabolic shape of a certain maximum depth (Read more).