[esp-r] An alternative to the compute-server fan boys - numerical simulation on a Raspberry Pi

[Jon Hand]

Business Card Simulation - Jon Hand, ESRU, Glasgow, Scotland, 19 July 2013

The Simulation Community is often seduced by the dark-side of speed and complexity.  Compute servers and thousand zone models have their fan-boys. And yet much of the work of creating and evolving simulation models takes a fraction of the computing power most machines deliver and lots of real-world simulation issues can be described via focused models and focused assessments. So lets open up our options, think outside of the box and explore a totally different scale of computing resource...

How about virtual physics via a full numerical simulation suite on a Raspberry Pi?  Lots of buzz around about these wee beasties. Pure-dead-brillient as we say in Scotland. It turns out that with a few tweaks in their setup and a few software tweaks on the simulation side they are also great platforms for exploring whole-building multi-domain simulation. 

A Raspberry Pi draws ~3W, is utterly silent, costs ~30 Dollars/Pounds, carries its OS on an 8GB SDHC card and has wee blinking lights that will keep you cat facenated. And it now runs ESP-r. ESP-r for Pi uses alternative header files that constrain model complexity (42 zones and 2K surfaces and lower CFD domain grid density and mass flow network nodes) but otherwise it has the same multi-doman feature set as the Enterprise/Linux/OSX/Windows versions. 

Blazing fast - not really. A normal 20 second assessment takes a couple of minutes.  Are you likely to be generating 2GB results sets or running massive parametric studies - not so often.  Coupled transient CFD on a Pi? Who knows, but at this cost point our current definition of deploying simulation is open for discussion.  I would certainly take a dozen of these beasties to a training workshop and plug them into local keyboards, mice and monitors rather than worry about software setup on unknown computers. I would certainly loan one to a student for project work. 

Folk used to any version of Debian Linux and/or OSX can just sit down and get to work on a Pi. The ESP-r Install script recognises the Pi as a build option if you want to make your own custom version or upgrade from the repository and re-compile.  Be warned though, building from scratch is going to take hours rather than minutes. Contact jon at esru.strath.ac.uk and I will send you instructions.

For those who have a Pi and want to avoid the hassles a pre-configured Raspbian with ESP-r distribution (pure-text, X11 and GTK interfaces), development tool-chain and source on an 8GB class 10 SDHC cards can be burned and shipped.  Contact Jon Hand at jon at esru.strath.ac.uk for details.