[Gary Vogel]

Hello, scientists. Maybe this is a long shot. I'm a graduate student at an agricultural university in the midwest. I have grain bins which I fumigated and took hourly fumigant concentration readings in. There are 23 points inside the bin, and I want to visualize the distribution/diffusion within the bins over time. I'd like to have a 3D wireframe animation showing the fumigant distribution, with, say, red showing high concentration and blue showing low concentration with a gradient in between.
I've been turned on to Tecplot as a visualization tool, but am COMPLETELY unfamiliar with using it. I'd like to just draw my geometry in AutoCAD and input the concentration data for each internal point and hit "GO", but it does not look that easy. I'm not looking for anyone to do this for me, but am looking for someone who has done work with Tecplot or a similar software who could navigate me through the necessary components.
Part of my project will also be modeling the gas flow in ANSYS Fluent, which I understand also will visualize the process, but only for modeling data, not actual experimental (recorded) data. Is that right?
Thanks for any help you can give.

[scott_rumage]

Your question is the classic starting point for designers that want to compare experimental results to computational results. My response will attempt to give you a guideline, but will not be a detailed step by step procedure:

1. The experimental data are 23 points inside the bin
2. Are these 23 points formed on some type of grid or mesh?
   i. If so load the grid and data into Tecplot using a Tecplot data format. Here is a link to our format guide: http://download.tecplot.com/360/current/360_data_format_guide.pdf
   ii. If not, then create a text file with t time, x position, y position, z position, and fumigant distribution (FD) as columns
3. Load this data into Tecplot via the general text loader.
4. Choose your x,y,z locations as the same points for when you will run the ANSYS simulation, i.e. use the same origin for the experimental and computational data

2. Once the experimental data are in Tecplot, the natural tendency is to create a “contour” plot on FD to see the distribution of the FD between collected points.
a. If you have a mesh, then Tecplot will create the contour plot automatically (as Tecplot will know the connectivity between the collection nodes),
b. If you don’t have a mesh (because you just read in t,x,y,z,FD values and Tecplot does not know the connectivity), then:
i. Create (or load) a grid in Tecplot
ii. Interpolate the experimental data onto the grid
iii. Once the interpolation is completed, Tecplot will be able to create a contour of the experimental data.
c. Once you are successful in creating the contour (or isosurfaces) of FD, you will probably be disappointed in the appearance of the contour plot. This is because you are using 23 points to try to describe a concentration in a volume (while your ANSYS simulation will probably use ~1,000,000 points to describe the same concentration).
d. Accordingly, as an engineer, you may want to think about how you will compare 23 points in experimental space with (1,000,000 points of) computational space. This work and visualization might be better done via comparative XY and 2D plots rather than volumetric plots.

3. Lastly, your experimental data are transient. So you will need to inform Tecplot that the “t” variable is time rather than another spatial dimension. You will do this by using Tecplot’s strand editor found along the top Menu Data>>Edit Time Strands>>

These notes are quite general, some tutorials and additional tips can be found in Tecplot’s documentation http://www.tecplot.com/support/documentation/ and http://www.tecplot.com/support/tutorials/ .

Good luck!
Scott