FlowVision 3.10.01

New appearance and new abilities for management of computational grid into the version 3.10.01

There are many improvements in the new version of FlowVision 31001. They significantly concern to functionality of adjusting and editing of computational grid such as computational grid adaptation, parameters of boundary layer grid etc. The list of main changes in comparison with FlowVision 31001:

  • All adaptations and boundary layer grid are specified now in separate section of project tree named “computational grid”
  • In project tree active adaptations and boundary layer grid are highlighted by color while inactive adaptations are grey-colored
  • Subregions and geometrical objects in PreProcessor with the same settings of computational grid can be grouped to single subsection of project tree. It is not necessary to repeat these settings separately for each item anymore.
  • It is possible to adjust a number of layers for intermediate adaptation levels (not only for maximal adaptation level as in previous version). It is not necessary to create such grid during several numbers of solution steps
  • New function is “adaptation by condition” which allows making split of cells according to specified condition (range of values for variables)

These and other most meaningful features are described below.

Read more: FlowVision 31001


About Radiation Models in FlowVision

When can the radiation model be used?

If the radiation heat flow is comparable with other heat flow, which is the main heat flow source in the problem (for example, convective heat flow), you have to use a radiation model.

The radiation heat flow can be evaluated based on temperature difference between surrounding environment and the body’s surface using the Stefan-Boltzmann’s law:

The formula above represents the low for the absolutely black body (Plankian radiator). For real bodies you have to multiply the value by emissivity factor.

Read more: About Radiation Models in FlowVision


FlowVision CFD – Frequently Asked Questions

  1. Installation and Licensing
  2. CAD
  3. Substances
  4. Grid Generation
  5. Solver
  6. Post-Processing
  7. Formula Editor
  8. Heat Transfer
  9. Turbulence
  10. Multi-Phase
  11. Moving Bodies
  12. FSI (Fluid Structure Interactions)
  13. Non-Newtonian & Visco-Elastic Rheology
  14. Compressible Aerodynamics
  15. Porous Medium
  16. Gap Modeling

Read more: Frequently Asked Questions


FlowVision CFD – Unique Capabilities

  1. Installation and Licensing
  2. CAD
  3. Grid Generation
  4. Post-Processing
  5. Formula Editor
  6. Heat Transfer
  7. Turbulence
  8. Multi-Phase
  9. Moving Bodies
  10. FSI (Fluid Structure Interactions)
  11. Compressible Aerodynamics
  12. Gap Modeling

Read more: Unique Capabilities


Small Cells and Their Role

What cells can be called Small Cells

In FlowVision uses Cartesian grid that can be automatically locally downscaled. Grid cells intersecting computational domain boundaries and computational subregions are clipped by boundary surfaces.

Fig.1. Splitting cells by geometry surface

Read more: Small Cells and Their Role


In this article you can read about choosing time step in FSI tasks.

Read more: Time Steps in FSI Tasks


At present moment, usage of PrePostprocessor (PPP) is officially supported only for Windows. However, sometimes it is necessary to run PPP on Linux too. Actually, customers of FlowVision have such possibility due to special software for running of windows applications on Linux, like Wine. Let us consider, how to run PPP on Linux using Wine, on the example of Ubuntu 16.04.1, and you will be convinced how easily it is.

Read more: PrePostprocessor on Linux


Most prevalent formats of 3D models for FlowVision are STL and VRML. Most of CAD allow to export 3D models to STL and VRML. SolidWorks also allows it.

In this article I will show what parameters of export in SolidWorks will be useful and allow achieving good accuracy of triangulation.

 

Read more: CAD Importing to FlowVision


It is very short article about post-processing in FlowVision. Just main idea which allow you quickly build several ColoredFD pictures.

 

Smooth Changing of Variable Value in FlowVision

Too quick changing of variable can give divergence or make convergence worse, because fast changes will give large gradients of physical variables.

For example, in tasks about turbines and compressors we have rotor which has large velocity of rotation. When we start simulation we can’t specify initial velocity for gas between blades of rotor, because structure of flow too complex. It means that during first time step we will have quick changes of velocity from zero (initial velocity of gas) to some large velocity of blades.

If we will solve this task for incompressible liquid, we will have divergence. It is possible to make convergence better if we will exclude too quick changes, for example, we can change speed of rotation smoothly from zero.

FlowVision allow to specify very complex equations for any user’s variables. Below you will find some formula template which useful to use every time when you need specify some smooth changing of variable.

Read more: Smooth changing of variable value in FlowVision


Parallel Simulation in FlowVision

In this article you will read about parallelization in FlowVision. It is necessary to understand several features, if you want to get a maximum from advantages of parallel simulations.

  • Why is not possible to accelerate simulation infinitely?
  • What is role of count of computational and initial cells in parallel simulations?
  • How to be faster?
  • What hardware is necessary to prefer?

Read more: Parallel simulation in FlowVision. What is necessary to know to be faster


Investigation of the Grid Convergence

When doing numerical hydrodynamic simulations, you certainly encounter insufficient accuracy of the obtained results. There can be many causes for this; one of the most typical causes is insufficient resolution by the computational grid.

Read more: Investigation of the Grid Convergence