. Shipbuilding and Shipping Record. iments. Four years before Froude presented the results of his more com-prehensive scheme of experiments, the famous Superintendent of theWasliington Tank, Naval Constructor (now Rear-Admiral) D. , gave a valuable paper on this subject to the AmericanSociety of Naval Architects and Marine Engineers. This paperwas entitled Some recent Experiments at the ModelBasm. The primary object of the experiments was the determinationof the power and efficiency of model propellers of the ordinarythrec-h\aded type, throughout the range of pitch ratio and blade
. Shipbuilding and Shipping Record. iments. Four years before Froude presented the results of his more com-prehensive scheme of experiments, the famous Superintendent of theWasliington Tank, Naval Constructor (now Rear-Admiral) D. , gave a valuable paper on this subject to the AmericanSociety of Naval Architects and Marine Engineers. This paperwas entitled Some recent Experiments at the ModelBasm. The primary object of the experiments was the determinationof the power and efficiency of model propellers of the ordinarythrec-h\aded type, throughout the range of pitch ratio and bladearea likely to be encountered in practice. The series of experimentscovered 30 model propellers. They were all 16 in. in diameter, threebladed, of uniform pitch, and very thin. The pitch ratio rangewas from -4 to l-S, and the disc areas experimented upon werefive in number ranging from -12 or -56 Experience has showii that the results presented would have beenof even greater use had the very low limits of pitch and disc area. 8 12 16 20 24 Z8 5cale por Slip per cemt. 32 5S 40 Fig. 8.—Taylors Curves of Propeller Efficiency (E), andPo-wer Co-efficient (S). of slip ratio) may be represented by a diagram where the abscissaeindicates values of slip ratio, the ordinates of the curve thecorresponding thrusts, and those of the curve , the coiTespond-ing efficiencies. (Fig. 7.) Prop. 2.—With given slip ratio, the thrust of a given screw variesas the square of the speed of advance through the water. Prop. 3.—With given slip ratio, and given speed of advance, andwith given design of screw and varying size the thrust varies as thesquare of the dimensions of the screws. Prop. 4.—With given slip ratio and given design of screw, theefficiency is unaffected by variations of speed or size of screw. Prop. 5.—(Consequent upon the four preceding.) A singlediagram such as that in Fig. 7 will represent the performance ofany number of screws of given design, but of differing
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Keywords: ., bookcentury1900, bookdecade1910, bookpublisherlondon, bookyear191
