A Method for calculating the Hydrodynamic Characteristics of Marine Propellers

This paper deals with the third problem of the propeller lifting surface theory in which the circulation distribution is obtained in relation with the geometry and the working condition of a propeller. In the problem, a two-dimensional integral equation has to be solved. In order to carry out the numerical solution reasonably, collocation method which is popular in the wing theory was applied to the propeller theory. In addition, the simplified non-linear theory with a constant pitch and the circulation reduction due to the viscosity were taken into consideration for the theory. Then, a practical method for calculating the hydrodynamics of marine propellers was completed and programmed for the computer.By using the circulation distribution of the propeller, the corresponding two-dimensional wing which has the same hydrodynamic characteristics as a propeller section can be derived. Then, the pressure distribution over the propeller blade was obtained by applying Moriya's method to the wing.