Comparison of different scaling methods for model tests with CLT propellers

CLT and other tip loading propellers designs can be checked by model tests as in the case of conventional propellers. In this paper the problem of the scaling of the model tests results of these propellers is reviewed. A way of solving this problem consists in the introduction of new procedures for scaling of the Open Water model tests results while maintaining the rest of the scaling procedures for resistance and propulsion tests. ITTC’78 standard method is widely used but some Institutes and Model Basins have their own more or less similar procedures. A series of technical approaches used for the scaling of Open Water tests results are presented here and applied to a reference case that has been very deeply studied in several Research Projects. The conclusion is that it is definitely necessary to use specific Open Water model tests results scaling procedure for CLT propellers in order to obtain full scale predictions with the same level of accuracy than in the case of conventional propellers.