Tips & Tricks

Parallel processing

“To pull a bigger wagon, it is easier to add more horses than to grow a gigantic horse.” This paraphrased quotation nicely expresses the basic concept of parallel processing. The speed of sequential computers has been doubling every eighteen months, according to Moore’s law. However, at any given time, that speed is limited by the state of the art in integrated circuit design and manufacturing. To circumvent that limitation, it is possible to split a given computationally intensive task among multiple processors working simultaneously.

The manufacturing of sand cores

The manufacturing of iron, steel and non-ferrous castings is achieved using a variety of casting process designs, and most of these involve the use of sand cores which form the internal shape of the casting. A good quality casting requires a good quality core. Dimensional stability, uniform density, strength, hardness and permeability are some of the characteristics that need to be controlled. A good core must have suffi cient strength and hardness to be handled and to resist during the pouring of liquid metal. Suffi cient permeability is also necessary for the escape of gases generated during the casting process. The diff erent manufacturing processes and some of the issues related to core production will be discussed here.

FLEXlm protection file system

ESI group needs to license, manage and track a variety of licensing options, platform and product dependencies. FLEXlm is one of the only software that is up to this task. A simple, shrinkwrapped license management product would not be powerful and flexible enough to license all ESI products.

Why it is useful to describe problems in terms of non-dimensional parameters and which ones are the main important in solidification?

A dimensionless quantity is a quantity without any physical units. Such a number is typically defi ned as a product or ratio of quantities which do have units, in such a way that all units cancel. Dimensionless quantities are widely used in the fields of physics and engineering but also in every day life.

Working with Solids in CFD-GEOM - Part 1: Boolean Operations

Given that today’s users may import several complex parts into CFD-GEOM, this tip will demonstrate how to use the Solid Boolean Union Option to combine several parts into one.

Using the BC/VC Queries tool in CFD-GEOM

Have you ever whished that you could blank/unblank or pick/unpick only interfaces in a CFD-GEOM model? You can now with the BC/VC Queries tool. This tool allows you to pick, unpick, blank or unblank all the interfaces of the current model based on the interface type (Fluid/Fluid, Fluid/Solid, etc.).

How to create Pyramid cells on structured-unstructured domain interfaces in CFD-GEOM

CFD-GEOM can be used to construct a variety of cell shapes: quadrilaterals (2D) and hexahedrals (3D) for structured meshes; triangles (2D) as well as tetrahedrals and polyhedral/honeycomb (3D) for unstructured meshes; prisms and pyramids (3D) for semi-structured meshes.

New Exposed Boundaries Visualization tool in CFD-GEOM

One of the various new features introduced in CFD-GEOM V2009.2 is the ‘Exposed Boundaries’ visualization tool. This tool allows users to quickly visualize those areas where closure problems remain in an otherwise closed and “watertight” model.

Repairing Imported CAD Geometries in CFD-GEOM

In most cases, importing CAD files in CFD-GEOM results in a clean geometry that can be directly used for further processing and/or meshing. However, for complex models, it is possible that the imported geometry has missing, untrimmed or defective surfaces that need to be manually repaired.

Butterfly Faces Meshing Tool in CFD-GEOM

In CFD-GEOM, a convenient meshing tool called "Butterfly Faces" allows the user to quickly and automatically create a structured mesh for circular topologies. The resulting mesh consists of 5 structured faces (4 sides and 1 core) inside a circle. Parameters are available to set the size of the core and the mesh density.