SpectraSim Documentation
Docs · Limits

Known limitations

Two SpectraSim features are marked Experimental — they run, but their results have not been verified yet, so treat them as indications, not as numbers to design with: the transonic SIMPLE and the pseudo-transient compressible solvers. Flow-generated noise is not included.

Last updated · Ahmad Abosrea — developer of SpectraSim

This page is the same list the program shows in Help → Known limitations, for version 0.6.0a1. Features marked Experimental run, but their results have not been verified; treat them as indications, not as numbers to design with.

Which features are Experimental?

Each of these works, but its results are not verified yet:

FeatureStatusWhat has been checked so far
Compressible flow with the transonic SIMPLE solverExperimentalIt does not crash, but it did not converge on either of the two mufflers tried (mass imbalance up to 26 % after 3000 iterations).
Compressible flow with the pseudo-transient (local time-step) solverExperimentalStable on both mufflers tried, but too slow to converge in a practical number of iterations (mass imbalance 5–9 %).

How should I use Experimental results?

As indications. An Experimental feature has no comparison against a reference yet, so its numbers can be used to explore a design but not to sign one off. The cases checked against measurements, exact solutions or a commercial finite-element code — with the reference type and the difference for each — are on the Validation page.

What are the general limits of this version?

  • Windows 10 / 11, 64-bit only. The flow solver is OpenFOAM, run as separate programs. Its Windows build cannot compile code, so features that need compiled code are not available.
  • Units are SI everywhere.
  • Projects work on a copy. A project opened from a file works on a copy in the runs folder. Results of earlier runs of the same model are kept in their own run folders and are cleaned up automatically after a while (File → Settings, File → Manage runs; Keep protects a run). Save the project to keep its results with it.
  • Mesh-independence studies with curvature sizing. A mesh-independence study in curvature sizing varies the fineness, which on curved walls changes the cells by less than a factor of two per step; the reported grid-convergence index there may not be reliable.
  • Flow-generated noise is not part of this version.
  • The technical Help is being completed. Articles marked Draft still lack their theory, typeset equations or references.
  • Explore mode without a licence. Without a valid licence, or after a trial or licence has ended, the program runs in explore mode: projects open, every step works and meshes can be made, but solving is not available. A run that is already going is never stopped. See licence activation.

How do I report something unexpected?

Use Help → Send feedback. It saves your note together with the logs in one zip; send it to support.