CFD

The use of computational fluid dynamics (CFD) in engineering applications generates tremendous amounts of data. We offer a set of newly developed FEMZIP data compression tools specialized for CFD data. Currently, we supported CEI's EnSight Gold format and OpenFOAM format.

EnSight Gold

A variety of CFD simulation results can be converted to the EnSight Gold format. Therefore, even if it is not your standard format, this format is a good way to test the potential of FEMZIP-CFD on your problems.

Usually, CFD results stored in the EnSight Gold format can be reduced by a factor between 5 and 10 depending on the simulation type. Output data from wind tunnel simulations can usually be compressed by a factor of over 5 for steady-state problems, whereas factors around 7-8 are achieved in the transient case.

CCM+
Compression of a stationary CCM+ result converted to EnSight Gold format with 71 Mio cells and 17 variables. FEMZIP-ENSG achieves a compression factor of 6.3.
EXA
Compression of a stationary EXA Powerflow result converted to EnSight Gold format with 8.6 Mio hexahedrals (*.fnc) and 14.3 Mio shell elements (*.snc). FEMZIP-ENSG achieves a compression factor of 7.6.

OpenFOAM

For OpenFOAM simulations, we support the formats starting from OpenFOAM version 2.3.0. The compression factors are about 5-8 for steady state models and up to 10-15 for transient models.

The SIDACT software products in the OpenFOAM area go far beyond a standard compression and decompression tool.
In addition to standard compression, we also offer on-the-fly compression that runs in parallel to OpenFOAM simulation. An application is particularly useful in cases where several time steps for postprocessing are to be provided. With this technique the data can be held on the local cluster disks. On basis of the compressed data evaluations can be made in ParaView with the help of our MPI parallel ParaView Plugin. If postprocessing on a local workstation is preferred, the simulation result can be summarized with our MPI parallel conversion tool, which replaces foamToEnsight. Especially for models with several time steps, our conversion tool is faster and more stable than foamToEnsight

Conversion of an OpenFOAM model with 960 processors, 80 million cells, 11 time steps and 11 variables, uncompressed size of 63GB. The tool foamToEnsight takes 5208 seconds for conversion. FEMZIP-FOAM converter based on the FEMZIP-compressed format takes 147 seconds.

The conversion of a model that has been divided among 960 processors, 80 million cells, 11 time steps and 11 variables has an uncompressed size of 63GB and takes 5208 seconds with foamToEnsight. The conversion based on the FEMZIP-FOAM compressed format using the FEMZIP-FOAM converter takes only 147 seconds. The result of the conversion step is a FEMZIP compressed model that is similar to the EnSight Gold format, but still contains the processor split.
During the compression and conversion processes, we determine metadata with the help of which we can significantly accelerate postprocessing, especially in EnSight. For a model with 253 million cells decomposed into 960 processors, the initial loading of the geometry with the standard visualization mode "2D full, 3D feature" is 2.5 - 3 times faster for FEMZIP-OpenFOAM converted data compared to the initial loading time of the same model in EnSight Gold format.

Time to Picture: Initial loading time for a 253 Mio cell OpenFOAM model split into 960 processors, "2D full, 3D feature" for data on local disc and cached data.

Products:

Supported Post-Processors:

  • FEMZIP-ENSG (EnsightGold)
  • FEMZIP-FOAM (OpenFOAM)
  • FEMZIP-ERFH5 (Meshfree)
  • EnSight
  • ParaView
  • BETA μETA

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