In the 19th century, a banker called Jordi Girona had a summer home in what was then a country region outside the Spanish city of Barcelona. Girona was a very religious man and attached to his splendid mansion was an equally splendid chapel. He died without heirs and his property was left to the Church and became a school for young men who wished to become monks. Years later, it became part of the campus of the Technical University of Barcelona; the house became home to the dean, the chapel was redundant, until the world renowned computer architect, Mateo Valero, decided it would be the perfect home for MareNostrum.

The power behind Desafio Espanol may not be a billionaire, but MareNostrum certainly has more “calculating power” than Ellison, Bertelli and ETNZ’s 30 millionaires together.

MareNostrum is a supercomputer; currently, the most powerful supercomputer in Europe. To put MareNostrum’s calculating capacity into terms a typical PC owner can appreciate; it has 10,240 IBM 2.3 GHz processors and 20 Terabytes of main memory. That doesn’t, however, mean that – if you went out and bought 10,240 PCs and joined them together, you would have the power of a MareNostrum. Those 10,240 PCs would, putting it very simply, work rather like a production line producing, for example, a car silencer – the first person would weld a seam on a rolled form, the second would insert one end plate and weld it in, the third would insert a pipe and so on; one job would follow on another, so nothing would be completed until the final person/processor in the chain had finished its allocated job.

MareNostrum’s processors don’t work like that! The architecture of this super computer is such that all those 10240 2.3 GHz processors work together, sharing the work of producing the end product, rather than passing each phase of the process on, the result is a capacity to perform a staggering 94.21 trillion operations per second!

When BYM News went to the launching of BMW Oracle’s USA 98, in 2006, one major design advantage that was stressed was that the Challenger of Record had access – via BMW – to “Europe’s most powerful super computer.” It is true that, at that time, Germany’s Juelich super computer was more powerful than MareNostrum, but not any more! The big advantage of access to Europe’s most powerful super computer now belongs to the Spanish, not the American, semi-finalist.

So how does a super computer help, where it comes to designing an America’s cup boat’s hull and keel? Francesc Subira, Associate Director of the Barcelona Supercomputing Centre explained things; stressing that he was over simplifying everything, so that a layman could understand.

Designing the hull of a boat is, actually, more complicated than designing an airplane, Subira said. The airplane just goes through air, whereas the boat travels through air and water. Given an ordinary computer, an airplane designer can only really come up with the best shape to overcome the effects of laminar flow. That is really a nonsense though, because the principle effects of air movement on an airplane are not laminar. As the plane passes through the air, molecules many metres ahead of the flight path are agitated; by the time those air molecules reach the nose of the plane, they are very agitated and remain so long after the plane has passed. So, the principle dynamic effect of a plane passing through air is not laminar, but turbulent, and even a very powerful, ordinary computer cannot calculate those effects. It would take it about 3000 years to do what MareNostrum can do in a month, so imagine how long it would take to do the calculations for a boat, where both air and water turbulence enter the equation.

Without a MareNostrum, a hull designer needs to build models for wind tunnel testing, with one that isn’t necessary, because it has been shown that when MareNostrum says “This is the best shape for that part of the hull.” wind tunnel tests confirm that. The supercomputer was not involved in Desafio Espanol’s first boat, its second one is a big improvement, but that is not the only way that MareNostrum is giving the Spanish team an edge!

Wind shifts can cause havoc with results; that was made clear to all on the last day of Round Robin 2, when BMW Oracle opted for the wrong side of the course and went from leading ETNZ to well behind, in a matter of moments, thanks to a massive shift. So, it is hardly surprising to know that a great deal of store is placed on gathering and analysing weather data. To enable all the teams to have good weather information, America’s Cup Management has installed 21 weather buoys around the racecourse area. Each of those buoys transmits a continuous stream of wind and weather data. Every team has access to that data that, via software developed by the Meteorological Data Service, is displayed in real time as a graphic wind field laid over an electronic chart.

Thanks to MareNostrum, Desafio Espanol has something more, as Professor José Baldasano, Director of Earth Sciences at BSC, explained. Since those buoys were installed, the weather data has been fed into MareNostrum on a minute, by minute basis and the supercomputer has analysed all that data. The result is that when Karol Jablonski takes Desafio out, his crew has a shift by shift, gust by gust forecast of what the wind will do, throughout the entire period of the race!

Valencia weather  

We couldn’t resist asking Professor Baldasano whether the much criticised Valencia weather, of Round Robin 1, was unusual.

“Yes and no,” he smiled “March and April are transition months and it is very difficult, even for MareNostrum, to make accurate predictions in a period of transition.”

The average wind forecasts that were a factor leading to Valencia being chosen as the 32nd America’s Cup venue were correct, but what Professor Baldasano pointed out was that those forecasts were based on broad data, for the Valencia region, not on the highly specific data, which is now available for the actual race courses and from a network of land based stations, which are essential to sea breeze prediction. In addition, during a transition period, averages tend to be just that – a daily average of 10 knots may be the result of 1 day with a 20 knot wind and 1 day with 0 knots of wind, so it is pretty meaningless in terms of forecasting actual racecourse conditions.

Summing up, Professor Baldasano said “Yes, the succession of almost windless days in April was unusual, but not that unusual.”

From now on, Valencia conditions should be very predictable, so the data MareNostrum supplies to Desafio Espanol will be very, very accurate and that could give the home team a big edge.