HPC for the big rigs

Last week Fortune Magazine published a profile on how Kenworth is using rented cycles in a server farm to put CFD to use getting your kibbles and bit cross country

Most people don’t spend much time thinking about mudflaps – those strips of rubber behind a big rig’s wheels that repel grime and maybe show a gun-toting Yosemite Sam, warning “Back off!” But by using sophisticated design technology, engineers at truckmaker Kenworth discovered that the little flaps were also a major source of drag. Simply trimming and tapering the flaps will cut about $400 from a typical truck’s annual gas bill.

How exactly did Kenworth solve its mudflap quandary? The company, a unit of $15-billion-a-year truck conglomerate Paccar, took advantage of cloud computing. In Kenworth’s case, engineers rented time on a supercomputer thousands of miles away; that system helped employees root out assorted gas-guzzling design flaws they might have missed had they relied just on computers at Kenworth’s facilities outside Seattle.

Kenworth had started with clay models in wind tunnels, but the process was expensive and time consuming.

Kenworth and its rivals later used in-house computers to simulate wind-tunnel tests, but the machines weren’t powerful enough to closely estimate what would happen with real air flowing around a truck at 65 miles per hour.

That kind of simulation requires dozens of the latest machines working together, a multimillion-dollar long-term investment that only the largest institutions can afford. A few years ago one of Kenworth’s aerodynamics experts learned that for roughly the price they had been paying to buy middling hardware, design-software maker Exa would sell them metered access to a cluster of IBM computers with enough speed to be called a supercomputer. (There’s no standard definition of a supercomputer – it’s what’s fastest at the time.) When Kenworth engineers saw that they would be able to get an idea of how a real truck would perform on the road, it was an easy call.