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Parachutes with an Axial Cord as Well as Cords Over the Canopy

出版	H.M. Stationery Office, 1944
URL	http://books.google.com.hk/books?id=aSZBGwAACAAJ&hl=&source=gbs_api

註釋The theory of a parachute with axial cord has been considered in a report by Richards, who assumed that the parachute was a surface of revolution. It can be shown however, that a parachute of this type can be designed which is much stronger than the parachute discussed by Richards. The basic principal consists in allowing the canopy to bulge out between the rigging lines so that the curvature of the surface is great. In this way the pressure difference which a given fabric can withstand without failure is increased. The theory of such a parachute having no axial cord has already been worked out in R. & M. 2320. In the present report this theory has been extended to cover the case where the parachute has an axial cord. Details are also given of experimental work which has been done on parachutes with axial cords. It is concluded that for a given bulk this type of parachute has greater drag and also a higher critical opening speed than the conventional type of parachute.