Phase Change in Fluids Simulated

brendotroy writes "After decades of work by the physics and computer science communities, scientists at the University of Rochester have finally created a mathematical model that will allow scientists to simulate and understand phase changes. This discovery 'could have an impact on everything from decaffeinating coffee to improving fuel cell efficiency in automobiles of the future.'"

Comments

Re:The decaf coffee

[gstoddart]

WHAT??? Why?? THe whole purpose of coffee is the caffeine. Caffeine is like water; without it, you just can't function.

Well, sometimes a good cup of coffe is what you want, but if you were to have any now you'd be wide awake for hours.

Sometimes, it's all about fooling the taste buds without affecting brain chemistry. :-P

Not what they're talking about

[MillionthMonkey]

Can it show why lakes don't freeze from the bottom up as water approaches 0 Celsius?

Freezing water is an example of a first order phase transition, involving a transfer of latent heat across a clearly defined phase boundary. Algorithms have been able to deal with those for some time (or so I assume). The big breakthrough here is that these guys figured out how to model a second order phase transition (i.e phase transitions in a supercritical fluid) without incurring infinite CPU time.

Most people are familiar with first order phase transitions (like melting ice or boiling water) but have never seen a second order phase transition. In general first order phase transitions involve a transfer of latent heat, and are noticeably discontinuous- the two phases are easily distinguishable from each other. Second order phase transitions do not involve a latent heat transfer and there is no abrupt discontinuity during the transition, as they occur above the critical temperature and critical pressure, beyond which the liquid and gas phases are indistinguishable.

The article doesn't explain this at all, but the giveaway here is that the reporter talks about the critical point.