Introduction

Visualization is a critical component of fluid flow analysis. CFD2000 includes an advanced scientific field visualization capability, that provides  access to a powerful set of analysis tools used to compute flow rates, examine re-circulation and boundary layer regions, or even track particle paths.

Visualization of simulation results is initiated either upon completion of a STORM solver run, or while execution is still in progress (i.e., “snapshot” mode).  Once initiated, all mesh values, boundary surface locations, and solution field variables from a STORM solution are loaded automatically. The visualization tools provide access to a wide range of advanced analysis capabilities such as cutting planes, iso-surface and contour map generation, streamlines and particle trajectory animations, data probes and profile plots. Surface integrals and customized scalar computations can be performed using the built-in CFD calculator.

Whole-field time-series animations, and cutting-plane/iso-surface sweep animations can be created and saved to AVI file format.            

Cutting Planes

An arbitrary cutting plane can be defined by using the Iso-Surface function. This plane can be positioned at any location in the CFD model (and at any angle). The cutting plane can be swept through the volume.

A coordinate surface (a special type of cutting plane) is defined as a surface of constant X, Y or Z.  The surface can be positioned anywhere in the model and animated along the coordinate axis. 

Cutting planes can be displayed in various modes:

              mesh       polygon edges only

              constant   shaded polygons with no surface lighting

              smooth     shaded polygons with scalar surface lighting

              contours   lines of constant value

              vectors    scalable, constant or scalar colored

Mesh

Contours

Streamlines

Streamlines are used to show the path of a particle by integrating through a vector field. Massless particles are placed in the flow field, with the integration performed based upon any vector function. A set of streamlines grouped together is known as a rake. Multiple rakes, each with any number of particles, can be created with the display attributes for each controlled separately.

By default, streamlines are displayed as solid, single-colored thin lines in the graphics window. However, many different options are available for displaying streamlines:  solid, dashed, spheres, dots, and ribbons.

Iso-Surfaces

An iso-surface is defined as a region where a specified function has a constant value. The surface can be based on any geometric or scalar function.  For example, an iso-surface can be created to show the regions in a model where the temperature is equal to a specific value. Iso-surfaces can also be animated to show a range of values in the model.

Boundary Surfaces

Boundary surfaces are used to show the various boundary types (e.g., wall, inlet, outlet, blockage) defined when the CFD model was constructed. Different types of boundaries may be grouped together and displayed as one surface, with all of the standard display options available for other surface types.  Boundary surfaces have one additional display type, Outline Edges (not available for other surface types), that will show the outline of the surface being displayed.

Particle Trajectories

STORM employs a Lagrangian Particle Tracking methodology for modeling two-phase flows involving liquid or solid particles. When a CFD model involves two-phase flow (e.g., particulates are introduced into the flow), a special visualization capability is required.  The time history (i.e., trajectories), and particulate attributes (size, temperature, etc.) can be visualized.

Animations

Solution Probes

Point probes are used to interrogate the scalar and vector values at a particular point in space. The locations being probed do not have to lie exactly on mesh points, as the values being displayed will be interpolated to the exact X, Y, Z location being interrogated.  Probes can be interactively placed, or exact X, Y, Z locations can be specified.

2D Graphs

Several different types of 2-D graphs are available:  line plots, open curve plots, closed curve plots, and XYZ curve plots.  Data pertaining to all graphs can also be imported/exported for data exchange between other analysis programs (e.g., MS Excel).

Functions Calculator

Functions can be created/defined using already defined functions, constants, or any pre-defined math functions.  Functions are created using a "Function Formula Specification" panel.