January 15, 2013

January 16, 2013, Jim Swain:
In my last posting I had fun with a technology preview on the Autodesk Labs site called Project Falcon.  I used this wind tunnel simulation tool to check the drag coefficients on a couple of pine wood derby car shapes:
A couple of things have happened since then which are having me go back and look at Falcon again. The first was Sandy. You can use whatever prefix you want for that storm, I am not looking for suggestions. Our family was very lucky, especially with my son going to school in Hoboken. He got to experience wind tunnel effects right there in his dorm!
In December add-ins were released for Inventor, Revit and AutoCAD.
Getting started is easy, just go to the ‘Getting Started’ page.
I installed the Inventor add-in and fired up a sample file from my Simulation CFD installation:

I suppressed the sample’s enclosing box and changed the units to feet.

And before anyone complains, I agree the model looks like it is out of a game. But it was already waiting for me on my system so I went with it!
In the Environments tab I had a new icon for Falcon Flow Simulation. Clicking on that launched Falcon right there in my Inventor session.
Right away I noticed two things: the Ribbon interface is very easy to navigate, and the flow direction can only be controlled in the XY plane.
So I put some assembly constraints between the parts and also between the parts and the Origin objects to get the houses to have their bases on the XY plane, with Z = 0. I adjusted the Domain Box to get the size closer to the model size. (It is shown in the picture just to give a sense of size.)

And here I’ve turned on the pressure results display.

That 0.009 psi reading seems small, but that wall has an area of about 256 sq. ft., so about 330 pounds of force with just a 35 mph wind. When I cranked the wind up to 70 mph the pressure jumped to 0.083 psi and the force on the wall is now over 3000 pounds. And the vacuum on the roof, shown in blue, is now 0.145 psi. If that was a 20 sq. ft. area the lifting force could be as high as 4000 lbf. Ouch!
Not bad set of results for about an hour of exploration. Now I have to get the Revit folks in the office to give it a try!
Best wishes for this New Year.
Jim Swain
Jim is Synergis’ Project Manager for Manufacturing Solutions and has been with Synergis since 1997.  Prior to joining Synergis he worked in the consumer electronics and automotive industries as a design engineer, a test engineer, and as a CAD administrator. He has also taught design classes at the college level. Jim’s broad knowledge base helps him to understand customers’ problems and offer appropriate solutions. Jim earned BS and MS degrees in Mechanical Engineering from Lehigh University. Jim is a certified Inventor Expert, having been in the first group of people to take and pass the Autodesk Inventor Certified Expert Exam at Autodesk University in 2003. He has also presented classes at Autodesk University since 2003.  Email Jim with a question or request.