As long as there is the pursuit for extra power there will always have to be a commitment to using more advanced and exotic materials. Exhaust design is no exception, and many exhaust systems - both classic and contemporary - provide us not only with engineering artwork but a technical challenge. One criterion expected of performance exhausts is their need to work at sustained elevated working temperatures, which has necessitated the use of more sophisticated and complex materials....

In the previous article on fasteners, we looked at a very clever design of threaded fastener that used a composite shank with the threaded portions of the component still produced in high-strength metallic materials. Not only do these fasteners use a polymer-matrix composite shank but, being made of multiple parts, they are, in the broader sense of the definition, a composite component. A European company has developed a new form of composite fastener that is a pure polymer-matrix...

A major factor in selecting any fuel for high-performance work is the ratio of the products of the reaction with the oxygen in the air to that of the reactants. In a liquid-fuelled space rocket, for instance, 1000 gallons of liquid oxygen will react with about 2000 of liquid hydrogen to create an exhaust gas many times the initial volume. This increase in volume escaping from beneath creates the thrust, which subsequently propels the projectile forward. Although experiments to use such...