Abstract
The stress distribution and the deflection of blades of various screw propellers in steady flow are computed by the thick shell finite element (FE) method in combination with the surface panel method. A new general method is proposed to estimate the bicubic surface parameters of the deformed blade and to resolve the non-linear relation between the FE displacement distribution and the geometrical parameters of blade profiles on cylindrical sections. The characteristics of the surface flow on rigid and deflected blades are computed applying an approximation by Taylor's series expansion and minimization of the perturbation velocities. A modified hydroelastic interaction procedure is employed to obtain correspondence between the deformed blade form and the generated pressure distribution.
For a few propellers with different blade outline, the flow and the deformation patterns are shown and two main trends of opposite changes of the hydrodynamic characteristics are emphasized. In each case we investigated the influences of the variation of designed spanwise thickness distribution on the performance of the propeller.
