International Shipbuilding Progress - Volume 18, issue 199

Authors: van Gunsteren, L.A. | van Hall, A.F.

Article Type: Research Article

Abstract: The requirements for propeller production are derived from desired hydrodynamic performance and mechanical properties. The usual requirements are shown to be sufficient for low and medium-speed vessels. For high-speed propellers cavitation is the determinant factor which is expected to evoke a trend towards more severe tolerances. An outline of the production process is given. Problem areas are identified. Production concepts are derived, based on the idea that a high-precision casting should be aimed at. The consequences for production methods are elaborated. It is shown that for the production process to be optimum with regard to quality and efficiency, an integration …is needed of mechanisation, computerized information processing and quality control. The proposed production conceptions, which already showed substantial improvements in quality and profitability, have been partly implemented. Show more

DOI: 10.3233/ISP-1971-1819901

Citation: International Shipbuilding Progress, vol. 18, no. 199, pp. 97-114, 1971

Authors: van Oossanen, P.

Article Type: Research Article

Abstract: In this paper some of the findings of an analysis of the experimental results of tests with eight propeller blade-section type profiles in two-dimensional, stationary, non-cavitating and cavitating flow in the large cavitation tunnel of the Netherlands Ship Model Basin are given. A method is developed to determine the more important stationary, two-dimensional profile characteristics in a potential flow and in water for both the non-cavitating and the cavitating cases. In water, the developed method was obtained from the findings of the analysis of the experiments and as such is limited to the flow conditions of those experiments. In this …method three general geometric profile form parameters are used to describe those profile form properties influencing the value of the lift coefficient and maximum pressure coefficient. With this set of general profile parameters a new propeller blade section shaping process may be developed in the form of a limited number of charts or relations valid for every profile form. It is seen that a relatively large radius of curvature of the leading edge of the profile is important in obtaining profile shapes insensitive to cavitation when the profile is subject to a range of incidence angles. Show more

DOI: 10.3233/ISP-1971-1819902

Citation: International Shipbuilding Progress, vol. 18, no. 199, pp. 115-130, 1971

Authors: Kuiper, G.

Article Type: Research Article

Abstract: This paper gives a brief review of the theory of unsteady lifting surfaces as applied to ships’ propellers. The possibilities and limitations of this theory are discussed, together with some results recently obtained by different authors. Mathematical methods of solution and their implications will be avoided wherever possible. The accurate measurement of unsteady forces acting on a propeller is rather difficult. Some investigations have been performed and the results of these are compared with results obtained with the lifting surface theory. Further systematic investigations are necessary and some suggestions for these will be given.

DOI: 10.3233/ISP-1971-1819903

Citation: International Shipbuilding Progress, vol. 18, no. 199, pp. 131-143, 1971

Authors: Forrest, J.

Article Type: Research Article

DOI: 10.3233/ISP-1971-1819904

Citation: International Shipbuilding Progress, vol. 18, no. 199, pp. 144-148, 1971