Abstract
Full-scale propeller performance is traditionally predictedby scaling model-scale test results, but the traditionalscaling methods do not take into account hydrodynamicdistinctions of tip-modified propellers in full-scaleperformance. An open-water CFD analysis is made onscale effects of tip-modified and conventional propellers,which are designed for the same operating condition withidentical propeller diameter and expanded area ratio.While model-scale computations are made with atransition model, a fully turbulent flow is modeled in the full-scale computations. The investigation on the effectsof the transition model shows that laminar and transitionalflow modeling is crucial in model-scale computations.Grid-independent solutions at model and full scale areachieved by grid verification studies.
The CFD analysis of scale effects shows that theefficiency gain of the tip-modified propeller is increasedat full scale. The difference of scale effects between thetip-modified and conventional propellers is related toalterations of tip vortex and sectional pressuredistributions by the bent tip and the higher spanwiseloading at the tip region of the tip-modified propeller.
The CFD analysis of scale effects shows that theefficiency gain of the tip-modified propeller is increasedat full scale. The difference of scale effects between thetip-modified and conventional propellers is related toalterations of tip vortex and sectional pressuredistributions by the bent tip and the higher spanwiseloading at the tip region of the tip-modified propeller.
Original language | English |
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Title of host publication | Proceedings of the Fifth International Symposium on Marine Propulsors - smp'17 |
Number of pages | 8 |
Publisher | VTT Technical Research Centre of Finland |
Publication date | 2017 |
ISBN (Print) | 978-951-38-8606-6 , 978-951-38-8607-3, 78-951-38-8608-0 |
Publication status | Published - 2017 |
Event | Fifth International Symposium on Marine Propulsors - Helsinki, Finland Duration: 12 Jun 2017 → 15 Jun 2017 |
Conference
Conference | Fifth International Symposium on Marine Propulsors |
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Country/Territory | Finland |
City | Helsinki |
Period | 12/06/2017 → 15/06/2017 |
Keywords
- Scale effect
- Unconventional propeller
- CFD
- RANS
- Transition model