Dear Colleagues:

A Happy and Joyous New Year to you all!

What a year 2012 was:  two structural window designs, three spectrometers, two cryogenic dewars and an extended-band imager.  Each of these was pressing the limits of the mechanical arts in one way or another.  Then there were the calls for help, or just to say hello, that filled the smaller spaces.  A great time. 

One recurring theme in my work has been the intersection of heat transfer, structures and optics.  The common issue is stability, either static or dynamic, of the optics.  This is a tricky combination because the three disciplines are, in most ways, mutually independent.  The trickiest part seems to be getting the heat transfer results (temperature fields) into the structural model in a reasonable fashion.  “Reasonable” is the key word here.  The engineer faces some difficult choices to achieve optical accuracies.

An approach, for design purposes, has been to linearize the radiation heat transfer and run the whole problem in a finite element code such as MSC/Nastran.  The temperature fields can be made to agree reasonably (there’s that word) well with the Sinda results, ~1% or so.  Import an AEH/Ivory optomechanical model of the image into the MSC/Nastran model and you have the ultimate thermo-opto-elastic engineering design tool.  Fiddle with the mechanics, either thermal or structural, and see the results in the image!  All in one computer model. 

An image from one of my instruments was featured on the cover of Aviation Week’s 75th anniversary issue.  (Well, yes, I have been at this a while.)

Now, most important of all…

Don’t forget our conference in San Diego in August.  Submit your paper abstracts at http://spie.org/OP303 and call me if you have questions. 

Now is your best chance to get in on the fun.

Here comes 2013….  Hang on tight.

Al Hatheway
1-8-13