1. My Airpak jobs are taking up too much disk space, what should I do?
2. How can I free-up disk space without deleting model, mesh and postprocessing files?
3. What are the three most essential files of an Airpak model?
4. What does "pack" and "unpack" mean?
5. How do I print out an Airpak model?
6. Where do I define my units?
7. How do I run a time-dependent or unsteady simulation?
8. What are initial conditions?
9. How do I include the effect of natural convection in my model?
10. What is the "Minimum object separation"?
11. What is the meaning of "Radiation temperature" on the "Problem/Setup" menu?
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My Airpak jobs are taking up too much disk space, what should I do?
Use "Cleanup" under "File" menu and delete mesh, scratch, and solution files
How can I free-up disk space without deleting model, mesh and postprocessing files?
You can compress the files using the "Compress" option under "File/Cleanup", or, you can delete the scratch files in "File/Cleanup" and save as much as 20% of the disk space.
What are the three most essential files of an Airpak model?
They are "job", "model" and "problem". These files contain all the information specified to build the model, such as the size and location of objects, properties of objects, problem setup data, mesh specifications, and solver settings. Any Airpak model must have atleast these three files.
What does "pack" and "unpack" mean?
The "Pack" and "Unpack" facility in Airpak allows you to communicate with Airpak support or with another Airpak user rather easily.
"Pack" means packaging the component files of an Airpak model (job, model and problem) into one file by tarring and zipping these files. You can send that file to Airpak support or another Airpak user for examination. The packaged file is named "jobname.tzr".
"Unpack" means unpacking a packaged job automatically. The unpack routine unzips and untars the zipped and tarred file and saves the component files "job", "model" and "problem" under the the directory "jobname", where jobname is the name of the model specified in the packaged job.
How do I print out an Airpak model?
First display the model in the Airpak inteface the way you want the model to appear in the print (including the size, view, shading, etc.). Then, in the options menu at the far right of the Airpak main inteface, click "Print" and save the image under one of the file formats allowed, e.g. gif, tiff, etc. You can then send the saved file to your printer.
Where do I define my units?
You can define units in "File/Configure". Click "Edit unit definitions" and define the units for any quantity (length, conductivity, power, etc.) and click "Set as default". The units so defined will be applied to any new object introduced into the cabinet. You can also alter the units of any variable of an object by editing the object and changing the unit definitions selected. To do this, just click the unit indicator beneath the quantity under consideration and change it to any other unit in the pick-list. The user also has the ability to simply set the type of units used for the entire problem to SI units or Imperial (English) units.
How do I run a time-dependent or unsteady simulation?
First select "Transient" by going to "File/Problem" and then specify "Start", "End time", "Time step increment", and "Solution save interval" of your simulation. Then go to "Solution/Setup" and specifiy the "Iteration/timestep".
What are initial conditions?
These are initial values of velocity and temperature that will be assigned to each cell in the mesh to serve as the first guess values for the solver. These are just initial guess values and are replaced by new values after the first iteration is completed. The default initial conditions are sufficient for most cases.
How do I include the effect of natural convection in my model?
In "File/Problem", toggle the "Gravity vector" and give the gravity value in the appropriate direction.
What is the "Minimum object separation"?
This is a value you specify in "File/Configure". It sets a tolerance limit where if any two adjacent faces are separated by a distance less than this tolerance limit, Airpak warns you of the situation. You may choose to cancel the meshing and examine the model for any errors or ignore the warning and go ahead with the meshing. It is not advisable to let Airpak make the changes automatically for it may make many unintended changes.
What is the meaning of "Radiation temperature" on the "Problem/Setup" menu?
"Radiation temperature" is the partial enclosure temperature applied when the default surface-to-surface radiation model is used. When a given surface radiates to some surfaces, normally all of the radiation does not reach these surfaces. The portion of radiation that doesn't reach these surfaces is assumed to go to the ambient maintained at a reference temperature called the "Radiation temperature".
