Automatic flow visualization method using self-organizing map

Abstract

In this paper, we propose a new visualization method using self-organizing map (SOM) for computed results of fluid flow. Most of existing visualization method gives color depending on a certain physical value, such as pressure, vorticity, etc. However the choice of the physical value is arbitrary and sometimes loses important features. The present method firstly classifies all flow properties, i.e. pressure, velocity components and their spatial gradients at each grid point, by giving these properties as high order vectors to SOM. Then color is given to each grid point based on its location on the map so that the flow field be naturally painted including all flow properties. SOM is originally a two-dimensional (2D) map as the main purpose of SOM is to visualize high order vectors, but in the present study the map is not directly viewed and only used to determine color of each grid point. Hence we try to generate three-dimensional (3D) SOM to give three color components based on the map. Both 2D and 3D map results are shown to demonstrate the capability of the present method.