OS X Version
Submitted by Anonymous on March 27, 2011 - 14:23
My company is currently in the market for CFD software which can do natural ventilation models for buildings (among other things). We would intend to import a Revit model of a building, perhaps make some minor adjustments to the geometery within the program if possible, input the required boundary info, etc. and run the model (i'm very new at this so forgive me if i left out a few dozen steps in between there). Which of your products, if any, would be best suited for us?
Also, I saw that you are coming out with a Mac version of this software as well. We would be very interested in this. When is this coming out? Is it in Beta release now, or in any form that we could try out?
[Edit: based on an email exchange]
Use of Multi-Cores in MAC OS X Version
Does the Mac OS X version of Caedium make use of multiple cores (parallel processing) to execute the underlying solvers? If so, how does its implementation compare with Windows OpenFLOW and Linux OpenFOAM in terms of processing speed (hardware being equivalent)?
Mac OS X version of Caedium does support multiple cores
Yes the Mac OS X version of Caedium does support multiple cores. For details try "Parallel Configuration". I haven't performed any benchmark comparisons between the different platforms.
Caedium for Mac OS X is out
If Revit can export geometry in the STEP format (preserves solids) then you are all set with the process you outlined.
Caedium can perform natural convection CFD simulations, for a tutorial try "Incompressible Transient Flow with Heat Transfer".
Given you'll need the Caedium RANS Flow, Builder, and Exchange add-ons, you will be best served by Caedium Professional.
The Caedium Mac OS X version was released almost a year ago.
Where to start?
I got the trial version of Caedium a couple of days ago and am trying to determine if (and how well) that I could use this software to analyze natural ventilation for buildings. Do have any recommendations of where to start to try to learn how to do this. I've been through lots of the tutorials on the website, and am still having a little trouble grasping it all, is there additional sources of info that I could be looking at? I've been trying several of the tutorials, but having issues not being able to duplicate the results for at least some of them (i.e. Internal Flow tutorial). Its pretty discouraging at this point that I can't even get the simple tutorials to work, much less, the kind of analysis that I'll need to be doing. Any suggestions?
Getting Started
If you haven't already, you might find it useful to read up on general fluid mechanics and CFD.
You might also review our screencasts for a more visual Caedium learning experience.
Tutorial wise I'd suggest working through the RANS Flow set.
We've tested these tutorials and for the latest version of Caedium they worked fine. Feel free to send me the Caedium project file (.sym) of the Internal Flow tutorial so I can diagnose the problem you are facing.
Are you using the latest version of Caedium? To check: Help->Check for Updates
Still Having Trouble
Thanks for your response I think that I'm learning how to build the geometry ok, but am having trouble getting the model to analyze air movement correctly. for example, in the Internal Flow tutorial.
The air should obviously be moving from the inlet to the outlet, and I'm pretty sure I'd followed the tutorial exactly, but it is not responding as I would think it should. I've since played with the model a little more so that's why it no longer looks exactly like the tutorial, but I'd love to know what I'm doing wrong. I'm currently evaluating a few CFD programs, including ANSYS, but would love to use Caedium instead since its much cheaper and runs on the mac and iPad (that was a cruel hoax!). I'd appreciate any advice you could give.
Substance State Incorrect
It sounds like you didn't set the Substance->State properties (Rotation and Viscous = No), review the 'Specify the Fluid Conditions' section in the tutorial "Internal Flow"
For reference here it is:
Select the Physics Tool Palette. Select Substances->Air. The Properties Panel will show the default properties for air. To enable incompressible, irrotational, inviscid flow, set the 5 properties under State (Compressible,Heat Transfer, Rotational, Transient, and Viscous) to No (if they are not set to No already).
Drag and drop the Substances->Air tool onto an edge of the volume. Select Done to set air as the fluid inside the volume.
Also using the Panel Flow add-on isn't going to cut it for natural convection, you are going to have to use the RANS Flow add-on as in "Incompressible Transient Flow with Heat Transfer".