Glossary

What are transonic airfoils, and what is the active clearance control? Check out our technical dictionary and find out more about engine technology terms – from active clearance control to velocity triangle.

HAE "Hell" "Hard" anodizing Hard chrome-plating Hardening and tempering Hardfacing Heat exchanger High-pressure compressor High-pressure turbine High-speed milling High-temperature vacuum brazing Hot isostatic pressing (HIP) Hypersonic aircraft

Heat exchanger

A heat exchanger consists of numerous coupled tubes through which a medium (e.g. air in an engine) flows. A second medium whose temperature differs from that of the medium in the tubes passes around the tubes. Thus, energy can be transferred from the hotter to the colder medium. In future engines heat exchangers will be used to return the residual energy in the exhaust jet to the compressed air upstream of the combustion chamber and, as a result, to considerably increase the engines' efficiency. Heat exchangers are already widely used in gas turbines, particularly for power stations.