CFD based propeller modelling and optimization

This report is written in fulfilment of deliverable D3.3 of the EU-FP7 project HyMAR. Aim of the project is to develop innovative hybrid drive train systems for small and medium size marine vehicles, by exploiting self-pitching propellers. In this context, the present report describes an automated optimal design procedure developed in the project and presents the results of applying this methodology to a practical self-pitching propeller design exercise. The proposed design procedure combines propeller hydrodynamics models by Blade Element Momentum Theory and Boundary Element Method with a general-purpose numerical optimization platform. Both models and corresponding numerical codes are developed by INSEAN. In the report, results of the validation of computational hydrodynamics models are presented through numerical applications and comparisons with numerical and experimental data from the literature. Next, results of a practical design exercise are presented and discussed. An existing self-pitching propeller model representative of current production by the propeller manufacturer partner of the HyMAR project is chosen as baseline configuration to be re-designed and optimised in terms of hydrodynamic performance. Main objective of the design exercise consists in achieving delivered thrust higher than the baseline in a given range of advance speed while hydrodynamic efficiency should not be lower than the baseline model. Numerical results of this design exercise are presented to demonstrate the capability of the proposed methodology to match design objectives.