Tips & Tricks

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.

Integer Cell Size Specification in CFD-VisCART

As it was explained in a previous tip called Understanding cell-splitting in CFD-VisCART and its effect on cell count, a small change in a specified cell size could lead to drastic changes in the cell count due to the cell-splitting rules used by CFD-VisCART.

Fit to View in CFD-VisCART

In CFD-VisCART, the 'Fit to View' function was improved in V2007. It now checks the blanking status before setting the view. In this tip, a car model will be used to demonstrate the Fit to View capability.

Coloring Surfaces in CFD-VisCART for Better Model Visualization

A typical model imported into CFD-VisCART may contain a number of parts and surfaces. By default, all surfaces come in with the default color (set under Edit → Preferences → Colors → Geometry Colors → Surfaces). Representing these surfaces with different colors would improve the appearance of the model and make it easier for the user to distinguish one surface (or part) from the other.

CFD-VisCART 'Save Image' feature

As in CFD-VIEW, CFD-VisCART has a 'Save image' feature that allows you to save snapshots of you model. If you are interested in this tip, please read on.

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.

Making it Easy to Add a Box Source in CFD-VisCART

Sources are used in CFD-VisCART to refine the grid in localized regions of the domain. One of the many types of sources available is the Box Source where the user specifies a cuboid box around the region a finer grid is required. In the earlier versions, the user would have to add a Box Source and then specify its X, Y and Z extents to position the box in the desired location.