by Steve Richardson
A Tale of the Hybrid Air/Conduction Cooled MicroTCA.2 Specification
When American Idol judge Simon Cowell uttered the phrase, “to be absolutely honest,” this was most often followed by a no-holds-barred critique, designed to pierce and punch as many holes in a hopeful Idol contestant’s ego and performance as possible.
Conversely, we tend to view singer-songwriter, Jimmy Buffet, as having a crowd of sixty to seventy thousand rabid fans parroting the chorus “Fins to the left and Fins to the right” in obvious delusional delight during any one of his annual concert tours. (I count myself as one of those multigenerational Parrotheads.)
Obviously, I’m very fond of the metaphorical and sometimes carry it a bit far – (I also miss Andy Rooney) – so how could Jimmy Buffet and Simon Cowell be synergistic? Right! They’re both richer than our wildest imaginations, but that’s not it. And it’s not that Jimmy can sing and Simon has mastered only the negative phrases of the King’s English.
It isn’t even that we have in Simon, a battle-hardened producer, and in Jimmy, a singing airplane pilot – although the air and the battle-hardened parts are a clue. More is revealed in the Buffet Anthem “Fins” where the chorus of “Fins to the left, Fins to the right” is characterized by the thousands of stadium fans with their hands skyward, palms together, waving rhythmically from left to right while joining in the lyric. Cowell’s annoying habit of punching holes in anyone’s performance is also legendary.
You see where this is headed, right?
These two Icons have unknowingly spawned the final installment in a four chapter subset of the MicroTCA specifications. The PICMG working group is finalizing the details for what will be abbreviated as MicroTCA.2. It is a hardened specification (designed to meet multiple levels of military shock and vibration environments) and it features the side benefit of hybrid cooling.
The forced air pathways, provided through a carefully crafted array of orifices in the sidewalls of the chassis, combine with the inherent conduction-cooling elements of clam-shelled AMC modules. Those same modules are coupled to the rugged chassis’ cold walls using hybrid vented card retainers.
Cooling fins would be employed along the clamshells for primary cooling of the higher powered modules using a flow through ventilation scheme proposed in the figure below,
Proposed MicroTCA.2
The resultant product will be the final planned addition to the more recently ratified dot specs. – Rugged MicroTCA.1, Conduction Cooled MicroTCA.3, and MicroTCA.4, which added rear transition modules to significantly extend the computational power of the platform for use in physics and timing applications.
MicroTCA.2 and its Mil environments are represented in the proposed chart above.
In early November Mark Leibowitz, BAE Systems Chief Systems Architect and Chair of the PICMG MicroTCA.2 working group presented a comparison of the ratified MicroTCA.3 Conduction Cooled platform and the proposed companion MicroTCA.2 platform at the annual Advanced/MicroTCA Summit. The two graphics included here were part of Mark’s presentation.
In mid November, an extensive characterization test was performed to validate the thermal capabilities of an exemplar Hardened Hybrid Air/Conduction Cooled MicroTCA.2 system. The results of that testing is expected to provide data, confirming not only the overall thermal behavior of typical slots populated with various combinations of high power, low power and filler modules, but also quantifying the contribution of thermal conduction to the sidewalls in the proposed specification.
It is anticipated that finalization of the spec and ratification will be completed early in Q1 2012.
A final thought: “Fins to the left” could be VPX, and “Fins to the right” could be MicroTCA.2.
Stay tuned for more shark sightings.
Steve Richardson is the CBT Technology (formerly XTech) representative on the PICMG MicroTCA.2 working group.
