Open-water test series with propellers in nozzles¹

Article type: Research Article

Authors: van Manen, J.D.

Affiliations: Netherlands Ship Model Basin at Wageningen

Note: [1] Paper read before the annual meeting, Nov. 1953, of the S.T.G. at Hamburg.

Abstract: This paper deals with open-water tests with propellers of the B 4-55 series in nozzles of systematically varied form. The results of the open-water tests with the “screw plus nozzle” combination are given for each form of nozzle in a Ks – Km – λ-diagram, as is usual with systematically varied series of screws [1, 2]. By means of these diagrams the optimum “screw plus nozzle” combination for the nozzle form under consideration can immediately be determined, while it is also possible to compare the efficiency with that of the screw without nozzle. A method is discussed for determining the translational velocity in the nozzle in the vicinity of the screw. The influence of the various parameters, decisive for the open-water “screw plus nozzle” combination, are examined as regards their importance. Finally, attention is devoted to the framing of a condition of minimum loss of energy for the “screw plus nozzle” combination, and at the same time directions are given for cavitation-free design of the screw in the nozzle according to the vortex theory.

DOI: 10.3233/ISP-1954-1205

Journal: International Shipbuilding Progress, vol. 1, no. 2, pp. 83-108, 1954