Overture plays on methods for faster, more accurate models
Posted July 31, 2007
Nobody would use a buzz saw to carve a toothpick. Nor would a sensible person use a crowbar to open a sardine can.
It takes the right tool in the right situation to get the job done quickly and efficiently.
Computational scientists face similar issues: When is a particular mathematical tool right for a particular simulation of a physical phenomenon?
Bill Henshaw helps answer that question. He designs and combines algorithms that computers use to simulate things like ice accumulation on airplane wings, cooling nuclear reactors, and even how a bomb explodes.
Most such simulations involve moving geometry – objects moving through space and interacting with fluids and other objects.
“That’s a very difficult problem for many computational people,” says Henshaw, an applied mathematician at the Department of Energy’s Lawrence Livermore National Laboratory in California.
For convenience or simplicity, researchers sometimes use a single technique or tool to attack such problems. That’s not always the best choice, Henshaw says, because as the object or area being modeled changes, the technique is less effective. It’s a bit like using a chainsaw to cut down an oak tree, then using the same saw to carve intricate designs on an eggcup made from the oak.
Henshaw’s research combines tools that automatically adapt to use the best ones for specific parts of the simulation. Different algorithms “behave better in different regimes, so you want to use the appropriate algorithm” where it’s most effective, he adds.
“Part of what I do is try to look at the existing good algorithms out there, design new ones that actually form composite or hybrid methods,” and apply them to complex problems, Henshaw says.
That’s the approach behind Overture, a set of tools Henshaw’s group developed to simulate physical phenomena such as fluid dynamics – the movement of liquids or gases, like water through a pipe or air over a car – , combustion and electromagnetics. Overture adapts the algorithm as the problem changes shape.
