The influence of the choice of propeller design tool on propeller performance
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- Institutt for marin teknikk 
In this master thesis different propeller design and analysis methods are presented and comparedin terms of the accuracy and computational efficiency of their theory. These methodsinclude lifting line, vortex lattice lifting surface and panel methods. A propeller design programbased on lifting line theory was developed by the author. This program has been used togetherwith the propeller design programs OpenProp and AKPD to make six propeller designs. Thedesigns are based on two sets of input data, making three designs for each set. Each propellerdesign has been analyzed for performance in the analysis software AKPA. Cavitation analyseshave also been performed. An effort has been made to include a CFD (Computational Fluid Dynamics)analysis as was initially intended. Eventually this is not included due to time limitationsand software issues. The objective of the thesis is to give recommendations regarding what isthe most suitable propeller software.The following conclusions could be drawn from the performed analysis on the two designprograms utilized in the thesis: Based on the propellers designs analyzed in this thesis, OpenProp is able to produce thebetter designs. Both of the OpenProp propeller designs achieves the highest efficiency aswell as showing the least cavitation. OpenProp has an advantage in time required to produce a design. It is able to designand run a performance analysis in a matter of seconds. AKPD requires several minutes toproduce a full design if the number of unsteady calculation iterations are set to 5 or above(which is recommended by the author for convergence). AKPD is the only design tool of the two which is able to account for effects from skew andrake. Skew is often preferred in modern propeller design in order to reduce cavitation,noise and vibrations. AKPD is set up for a seamless transition to AKPA. If AKPA is the preferred analysis program,making the designs in AKPD may end up saving time in the design process. While both AKPD and OpenProp are restricted to circumferentially averaged inflow, AKPDiiican account for inflow in the radial as well as the axial and tangential direction. This mightbe of importance for propellers with high shaft angles or high rake.