Tips & Tricks

Motion Model Dependencies in CFD-FASTRAN

Moving-body models available in CFD-FASTRAN are highly suited to simulate complex prescribed and six-degree-of-freedom (6DOF) motions of rigid bodies. In many engineering problems, this translates to multiple bodies moving relative to one another.

Creating Multiple Blocks from a Single Mouse Click

Computational Fluid Dynamics initiated in structured grid context for smooth and orthogonal structured grid on relatively simple geometries. Today, CFD has evolved encompass multi block and overlapping structured grid techniques for complex geometries, along with other mesh types such as tetrahedrals, polyhedrals, and prisms.

Handling Multiple holes for surface operations in CFD-GEOM

In the past, cutting or filling holes in surfaces with CFD-GEOM required a two step process; 1) pick the surface 2) pick the closed set of curves that forms the hole. Not a bad process but in the case of having to cut the surface with multiple holes, it was quite inefficient since you could only cut one hole at a time.

Edge Substitution for surfaces in CFD-GEOM

The Edge Substitution tool in CFD-GEOM is designed to make it easy to modify surface boundaries. It allows you to replace the lines/curve of a surface with edges, and vice versa.

Local Curve Meshing in CFD-GEOM

Computational geometries/assemblies often involve parts that may vary in scale. Although unstructured surface meshing adapts to the size of the geometry, in some cases there may not be sufficient grid density in specific regions of your model.

Geometric Precision and Filtering in CFD-GEOM

In many cases, CAD models can be dirty and thus do not import well into CFD-GEOM. Repairing these geometries can often take considerable time and effort. Many times, duplicate points, lines, and surfaces are created when importing CAD geometries.

Low Mach Preconditioning and Dual Time Stepping in CFD-FASTRAN

Density-based schemes employing time-marching procedures available in CFD-FASTRAN provide excellent stability and convergence characteristics for high-speed compressible flows (typically M >0.5).

Axisymmetric 2D Convergent-Divergent Boattail Nozzle Simulation Using CFD-FASTRAN

The NASA D-1.22-L boattail nozzle configuration was obtained from the MADIC (Multidisciplinary and Design Industrial Consortium) program. The geometry definition and the flow conditions are documented in NASA TP 1766 [1]. This user tip presents a validation of numerical methods against experimental data.

Parametric studies using CFD-GEOM and SimManager

Parametric studies controlled by SimManager give the useful ability to perform several routine simulations. It allows to use CPU time more effectively and reduce user interaction. In other words, it is possible to automate the process of mesh generation in GEOM, model setup in CFD-AGE-GUI, solver run, and visualization in CFD-VIEW. In this user tip, automatic geometry manipulation and mesh creation will be discussed.

Semi-Structured Domain Stitching in CFD-GEOM

A feature that allows users to stitch together a Semi-Structured domain is available in CFD-GEOM. This feature gives the user flexibility of stitching two end faces with different topologies, i.e. a geometry that cannot be extruded.