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.

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.

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.

Using "Visual Scaling" for Models with Drastically Varying Length Scales

For models that have drastically varying length scales, it can be difficult to create the grid, setup a model, and post-process the results. CFD-GEOM, CFD-ACE-GUI and CFD-VIEW have a "Visual Scale" capability that can significantly help when working with these types of models.

Parametric Studies Using SimManager

Parametric studies are an important aspect of CFD analysis. Parametric studies are used to perform trend base analyses, optimize the deign of a device, and/or to study the affect of different parameters on a process (What if? type analysis).

How to Compare the Model Setup Between Two DTF Files

Have you ever wanted to find the differences between two DTF files? If you have, then you will probably be interested in a DTF utility included in your ESI Software installation. The utility is called dtf_diff and can be found in your UTILS_2009.0/bin directory.

CFD-ACE+ and CFD-TOPO Coupling

There is a growing demand and challenge in different industries, especially semiconductor and MEMS areas, to have increased wafer size with reduced feature size, i.e. high quality process uniformity.