FINFLO RANS-Predictions for Propeller Performance

Performance of the PTTC propeller has been investigated numerically according to the instructions given in the Propeller performance -workshop of SMP’11 symposium. The calculations have been performed by the RANS equation solver FINFLO. The workshop tasks included prediction of propeller open water curves, propeller wake field, and cavitation behavior at three different operation points. Model experiments were made for comparison to calculations at SVA Potsdam towing tank and cavitation tunnel. Only some global performance characteristics have been released to the participants prior to the workshop. The calculations for the wake field and cavitation predictions were conducted according to a thrust identity relative to measurements. The advance speed of the propeller had to be increased slightly in the calculations to reach the thrust identity while the propeller rate of revolutions was kept unchanged. The propeller wake field was captured reasonably but a denser grid should be created in order to reach better grid convergence. The influence of the turbulence model should also be investigated. The cavitation predictions show a qualitatively reasonable behavior. The thrust breakdown of the propeller was due to pressure side cavitation at the blade leading edge.