home_activities-300x178Computational fluid dynamics (CFD) is a technique that uses numerical algorithms to solve and analyze flows problems.

In general, CFD analyses cover 5 steps:

  • The first step is creating a simulation model. This is mostly based on a CAD drawing from a customer. In general the CAD drawing contains a lot of details that are obsolete for flow analysis. Therefore, some time must be spend on CAD cleaning
  • The second step is the mesh generation. The fluid domain has to be discretised using numerous volume elements. See the menu on meshing for some details.
  • Step three, is setting up the model, defining boundary conditions, selecting physical models, specifying multiphase settings, etc. If information for boundary conditions are lacking, it is recommended to perform additional measurements. See the Experiments menu for some details.
  • Solving the model is covered in step four. This is mostly done on Omnia’s server, or in the cloud, if CFD-models become too large, or if customers demand this.
  • Step five covers the postprocessing in which the results are summarized in qualitative figures and quantitative numbers. This step is considered as the most laborious step since it is not always simple to visualise the occuring phenomena in line with the customer’s expectations .

Omnia Engineering always uses commercial software packages (ANSYS CFX, Fluent of Star-CCM+) since these provide solutions in the shortest times. Depsite the fact that licenses costs money, the shorter throughput time mostly pays off.

Omnia Engineering uses Finite Volume Packages, since Finite Element Methods are not considered accurate enough.