August 11, 2021
Free surface is the surface of a fluid that is subject to zero parallel shear stress, such as the interface between two homogeneous fluids, for example, liquid water and the air in the Earth’s atmosphere. Unlike liquids, gases cannot form a free surface on their own. Fluidized/liquified solids, including slurries, granular materials, and powders may form a free surface.
A liquid in a gravitational field will form a free surface if unconfined from above. Under mechanical equilibrium this free surface must be perpendicular to the forces acting on the liquid; if not there would be a force along the surface, and the liquid would flow in that direction. Thus, on the surface of the Earth, all free surfaces of liquids are horizontal unless disturbed (except near solids dipping into them, where surface tension distorts the surface in a region called the meniscus).
In a free liquid that is not affected by outside forces such as a gravitational field, internal attractive forces only play a role (e.g. Van der Waals forces, hydrogen bonds). Its free surface will assume the shape with the least surface area for its volume: a perfect sphere. Such behaviour can be expressed in terms of surface tension. It can be demonstrated experimentally by observing a large globule of oil placed below the surface of a mixture of water and alcohol having the same density so the oil has neutral buoyancy.
In this tutorial you will lear how to simulate a hydraulic jump using DesignModeler, Ansys Meshing and Ansys Fluent.
In this tutorial you will learn how to simulate a Flow through Porous Media using Ansys CFX.
The NACA four-digit wing sections define the profile by:
First digit describing maximum camber as percentage of the chord.
Second digit describing the distance of maximum camber from the airfoil leading edge in tenths of the chord.
In this tutorial, you will learn how to simulate a blower (unsteady) using Mesh Motion with Ansys Fluent. Please download the mesh.
In this tutorial you will learn how to simulate a Blowe using Ansys Fluent through multiple reference frame.
In this tutorial you will learn how to simulate a multiphase simulation through lockExchange tutorial that comes by default with OpenFOAM.