How to... analyze and measure model in postprocessing CFX / Fluent Ansys

After many analyzes, we come to the conclusion that each elaboration of the results looks similar (sometimes identical).  Then it's time to diversify our report with new indicators and charts.  Ansys postprocessing offers many possibilities.  First of all, we can display our output with different configurations of contours, velocity vectors or isosurfaces.

Path to generate measuring  lines

In addition to the variants of presenting the results, we can also make changes to the graphic design.  Contours or vectors can be displayed in various colors, in shades of gray, inverted rainbow, etc. As for vectors, apart from colors, you can also change the shape and size of indicators.

In addition to the basic variants of presenting output data, it is also worth using the generation of charts based on selective data and their export to external programs.  

Today I will present how you can select data using measurement lines.  Then I will show you how to generate a chart based on defined lines, what variables can be analyzed, and how to adjust the chart to our requirements.  Of course, I will also explain the differences between the three basic chart types.

The first step in sectioning the data from the model using lines is to select the INSERT - LOCATION - LINE path.  After selecting the above option, the details of line 1 window will appear.  Select the domain on which the measurement line will be defined from the red frame.  In the definitions field, we need to place our line.  Click on the starting point (point 1, in one of the three white rectangles).  Then click on Point 2 (analogous to the starting point), all the time we working in the blue frame.  The last stage of defining the line is to determine how many points we want to generate along its length (i.e. what the measuring accuracy should be).  This option is in the yellow frame.

Option window for line edit 

After generating one line or as many as you need, it is time to define the graph for your selective data.  According to the REPORT - INSERT - CHART procedure, we create a chart.  After generating the chart, the options window appears.  

In the next four steps, we define what data will be presented and how.  In the first window, select the type of chart.  As mentioned before, we have three main types.  Graphs typically for selective data, transient graphs for presenting data over time and histograms mostly for presenting statistical data.

How to add chart

We choose the first option for selective data (we can also give a title to the chart) and go further to window 2. In this workspace, we define a series of data, naming it and assigning it to specific selective data (lines, point clouds, etc.).  In window 3 we choose the variable X. We can also adjust the scale here, eg logarithmic for very scattered data.  We go to the last window where we select the variable Y (we can adjust the axis scale in the same way).

Path  for  define  chart

An important option that I mentioned at the beginning of this post is the export of post-processing data to a CSV file.  This can be done in two ways: from the level of the main menu or from the level of the generated graph.  The export function is located on the lower buttons of the graph options window.  

Data processing in other programs (eg Excel) can help us to compare the data from numerical analyzes with the actual validation experiment.  Also developed statistical functions in these external programs / applications such as regression analysis can enrich our report.

Remember that when you export data from many generated lines, planes or points, they will be arranged in a CSV file in one row of columns.  This is a different structure compared to the data exported from the charts from the solver level.  There, the data is arranged in more columns corresponding to the number of curves on the chart.