Pressure Forces on Variable Conical Nozzles

• Published in: Aircraft Engineering and Aerospace Technology Vol. 33; no. 4; pp. 100 - 102
• Main Author: Woods, W.A
• Format: Journal Article
• Language: English
• Published: MCB UP Ltd 01.04.1961
• ISSN: 0002-2667
• DOI: 10.1108/eb033397

REHEAT systems for turbo-jet engines employ variable area convergent nozzles, and modern developments have produced nozzles made up of a series of flaps or fingers, as shown in fig. 1. These flaps have to be supported against the internal gas load to maintain a given area. The turning moment on each flap is usually balanced by a single element through a mechanical linkage; the element may take the form of a rod in tension or a shaft in torsion. This note provides a theoretical study of the nature of this load. In addition, the concept of frictional forces is introduced and a method developed for calculating the forces prevailing in flight, provided that two constants are determined from sea level test results.