Continuously fueled combustion engines, on the other hand, produce lots of power per pound, partly because they don't need to carry all of their latent energy inside. In a turbojet engine, for instance, the outside air is pulled in, compressed by spinning blades, and mixed with atomized fuels. The blend is then ignited in combustion chambers to create a powerful thrust. Unfortunately, these engines are large, heavy, and hot. The simplest and most efficient way of pulling current out of chemistry is the fuel cell, which is based on the scientific concept of electrocombustion.
Fuel cells work by combining oxygen, which has a fierce passion for electrons, with hydrogen.
When the two elements are introduced, the oxygen goes insane with electron desire. The basic idea for electrocombustion was hit on as far back as 1839. In practice, however, hydrogen and oxygen are tricky substances to work with, so electrocombustion rapidly leads to bulky, expensive structures. That could be changing. Romesh Kumar, a fuel cell technology specialist at Argonne National Laboratory in Argonne, Illinois, says this development is made possible in part by computational fluid dynamics, a computer-based simulation technique.