The influence of the choice of propeller design tool on propeller performance

In this master thesis different propeller design and analysis methods are presented and compared\nin terms of the accuracy and computational efficiency of their theory. These methods\ninclude lifting line, vortex lattice lifting surface and panel methods. A propeller design program\nbased on lifting line theory was developed by the author. This program has been used together\nwith the propeller design programs OpenProp and AKPD to make six propeller designs. The\ndesigns are based on two sets of input data, making three designs for each set. Each propeller\ndesign has been analyzed for performance in the analysis software AKPA. Cavitation analyses\nhave also been performed. An effort has been made to include a CFD (Computational Fluid Dynamics)\nanalysis as was initially intended. Eventually this is not included due to time limitations\nand software issues. The objective of the thesis is to give recommendations regarding what is\nthe most suitable propeller software.\nThe following conclusions could be drawn from the performed analysis on the two design\nprograms utilized in the thesis:\n Based on the propellers designs analyzed in this thesis, OpenProp is able to produce the\nbetter designs. Both of the OpenProp propeller designs achieves the highest efficiency as\nwell as showing the least cavitation.\n OpenProp has an advantage in time required to produce a design. It is able to design\nand run a performance analysis in a matter of seconds. AKPD requires several minutes to\nproduce a full design if the number of unsteady calculation iterations are set to 5 or above\n(which is recommended by the author for convergence).\n AKPD is the only design tool of the two which is able to account for effects from skew and\nrake. Skew is often preferred in modern propeller design in order to reduce cavitation,\nnoise and vibrations.\n AKPD is set up for a seamless transition to AKPA. If AKPA is the preferred analysis program,\nmaking the designs in AKPD may end up saving time in the design process.\n While both AKPD and OpenProp are restricted to circumferentially averaged inflow, AKPD\niii\ncan account for inflow in the radial as well as the axial and tangential direction. This might\nbe of importance for propellers with high shaft angles or high rake.