File:A manual of marine engineering- comprising the design, construction, and working of marine machinery (1907) (14764250164).jpg

Identifier: marineen00seatmanualofrich (find matches)
Title: A manual of marine engineering: comprising the design, construction, and working of marine machinery
Year: 1907 (1900s)
Authors: Seaton, Albert Edward, 1848-1930
Subjects: Marine engineering
Publisher: London, C. Griffin and company, limited New York, D. Van Nostrand co.
Contributing Library: University of California Libraries
Digitizing Sponsor: MSN

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d while that of the propeller isincreased. For instance, if the blades of a large marine turbine were tohave a peripheral speed of 300 feet per second—which is often exceeded inland practice—and the screw propeller were to retain its normal speed of,say, 90 revolutions per minute, the diameter of the rotor would be 64 feet.Needless to say, this is impossibly big, and in practice the blade speedwould be cut down to about one-third this value, while tlie revolutions perminute would be doubled or trebled. This reduction in the normalperi))heral and rotational speeds of the turbine profoundly influences bothturbine and propeller. It is very nearly true that the number of stagesrequired varies inversely as the square of the blade speed, so that reducingthe mean effective blade speed by 50 )ier cent, will quadruple the numberof stages. Also, the diameter of rotor necessary to attain a given blade ♦ The. Theory of the Steam Turbim, by A. Jude. (Charles Griffin & Co., London, 1906.)
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