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A simple duct or specially shaped tube that draws in air resulting from forward speed or the ram effect, compresses it, and then makes it flow over some heat source. The air is then ejected at a speed higher than at entry. In this arrangement, there are no moving parts, and the system can work only at a forward speed. The short form for aerothermodynamics duct is athodyd. Also known as a ramjet.
An Illustrated Dictionary of Aviation Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved