future of RC: A new millennium in modeling, The

Model Airplane News, Jan 2000 by Aberle, Bob, Gierke, Dave

The horizontal piston engine offers advantages that may be attractive to the RC community: small frontal area, high power-to-space ratio, power multiplication versatility, extremely low axial and radial vibration levels, multi-fuel capability, glow or spark ignition option, moderately low rpm, high torque and low exhaust and propeller noise levels.

FUEL CELLS

For electric motor operation, the fuel cell offers hope for a lightweight, high-energy density alternative to the chemical battery. The fuel cell converts chemical energy directly into electricity without combustion as an intermediate step. Fuel cells are similar to batteries in that they both produce DC current by means of an electrochemical process. Fuel cells are different from batteries because they store their reactants (hydrogen and oxygen) externally and operate continuously, as long as they are supplied with fuel.

Fuel cells are combined into groups called "stacks" to achieve useful voltages and power output. As with all developing technologies, there are a number of unresolved critical issues such as weight and fuel conditioning, but this is one to watch.

Author's note: special thanks to Frank Vassallo-my partner in aeronautical investigation-for his valuable assistance in the preparation of this article.