Tips & Tricks

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.

Chemical-kinetic Model for Mars Atmosphere Re-entry Applications

The shock layer flow over a blunt body entering a planetary atmosphere at a hypersonic speed will dissociate and partially ionize. A reliable prediction of the flow-field for such application requires a chemical-kinetic model. For Mars atmosphere, the five species Park'94 is considered [1]. The dissociation of CO2 is producing C, CO, CO2, O and O2.

Improvements to Parallel Simulation Setup in CFD-FASTRAN

Setting up and launching a parallel simulation has become much simpler and easier in FASTRAN. This note discusses some of these developments. Let’s start with things that have not changed. There are still two versions of CFD-FASTRAN solvers for parallel cases. The difference between the two versions is the underlying parallel communication mechanism, the choice of which is decided by the type of mesh used.

Simulation of the Hypersonic Flow Past a Blunted Cone-cylinder-flare (HB-2) using CFD-FASTRAN

Study of supersonic flows is of high interest for a wide variety of problems including design of high speed planes and other related applications [1]. This user tip presents a validation of numerical methods against experimental data.

Transparency Feature in CFD-GEOM

In CFD-GEOM, certain entities can now be set to transparent. This option allows you to add transparency effects to your surfaces, faces, and volumes. This can be an excellent way to add shadows/colors and glass effects to the model.

Using the Construction Plane in CFD-GEOM

Point entities in CFD-GEOM are placed in an XYZ (Cartesian) coordinate system. The Construction Plane tool enables you to position a plane in space, and place points on that plane to generate curve entities.