Definition length for the Oortmerssen method. The prediction is valid for deep and calm water, and has the following applicability:. Input data resistance prediction 2. Hollenbach, for displacement vessels. It is possible to adjust the hull characteristics by changing secondary parameters.
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Introduction In a recent publication [ 1 ] a statistical method was presented for the determination of the required pro- pulsive power at the initial design stage of a ship. This method was developed through a regression analysis of random model experiments and full-scale data, available at the Netherlands Ship Model Basin. Because the accuracy of the method was reported to be insuf- ficient when unconventional combinations of main parameters were used, an attempt was made to extend the method by adjusting the original numerical predic- tion model to test data obtained in some specific cases.
This adaptation of the method has resulted into a set of prediction formulae with a wider range of applica- tion. Nevertheless, it should be noticed that the given a tentative character only, because the adjustments are based on a small number of ex- periments. In any case, the application is limited to hull forms resembling the average ship described by the main dimensions and form coefficients used in the method.
The adaptation of the method to naval ships was carried out in a research study for the Royal Nether- lands Navy. Permission to publish results of these studies is gratefully acknowledged. R TR additional pressure resistance of immersed transom stern R A model-ship correlation resistance.
For the form factor of the hull the prediction for- mula: can be used. In this formula C P is the prismatic coefficient based on the waterline length L and lcb is the longitudinal position of the centre of buoyancy forward of 0. In the form-factor formula L R is a parameter reflecting the length of the run according to: The coefficient c 12 is defined as: In this formula T is the average moulded draught.
The coefficient c 13 accounts for the specific shape of the afterbody and is related to the coefficient C stern ac- cording to: For the coefficient C stern the following tentative guidelines are given: Afterbody form.
SHIP RESISTANCE PROPULSION PREDICTION-HOLTROP MENNEN METHOD
Holtrop and Mennen' method in EXCEL spread sheet