Design methodology of a flexible composite propeller by coupling structural and hydrodynamics simulations
Topic(s) : Industrial applications
Co-authors :
Marion LARREUR (FRANCE), Thibaut ALLEAU (FRANCE), Gabriel HEGUY (FRANCE), Elamine GHEFFARIAbstract :
CoPropel is a European project which puts forth a holistic approach to develop and mature an innovative composite propeller for next generation vessels. Compared to their traditional metallic counterparts, marine composite propellers have numerous benefits, such as: low vibration with reduced noise emission, lightweight with a mass reduction of between 50% to 60%, and higher specific strength. Besides, due to the rigid properties of metallic materials, they are designed for a single operating condition and not optimal for other speeds or sea conditions, while the flexibility of composite makes it possible to adapt the shape to off-design points.
The proposed technology for the design is based on the bend-twist coupling characteristic of composites. The anisotropy created by the stacking of layers with optimized angles, taking into account manufacturing constraints, makes it possible to design flexible blades by controlling the stiffness and strength in a desired direction. The shape of the composite propeller, and more precisely the pitch (difference of deflection between the trailing edge and the leading edge), adjusts to the loading induced by the perceived flow, leading to an increased performance over a wider range of operating condition. The designed propeller is based on a reference metallic propeller, the shape will be the same at the design point to allow comparison. The geometry of the composite blades to be manufactured must be calculated with repulsive loads to obtain the unloaded shape, that will deform under pressure and match the reference.
A methodology coupling FEM and CFD models, calculating the hydrodynamic performance, deformations, stresses, and estimated frequencies of the propeller, is developed in this project. Calculation iterations must be performed due to the change in pressure distribution with deformed geometry, and the variation of the shape with pressure loads. Separated models are selected for fluid and structural simulations to limit calculation time, allow different meshing, and perform independent analysis. Sensitivity of element types, materials, and optimization algorithms is carried out with finite element models. An adaptative meshing technique based on error refinement is applied to model the fluid response and was validated across experimental and numerical data. Furthermore, it was observed that few iterations are necessary to obtain convergence of deformations and pressure loads.
The developed methodology will be validated with model and full-scale tests, with measurements to quantify the economic and environmental gains. This work will also be conducted in connection with the applicable norms and reference standards.
This project has received funding from the European Union’s Horizon Research and Innovation Actions, under grant agreement No 101056911, project CoPropel "Composite material technology for next-generation Marine Vessel Propellers.
The proposed technology for the design is based on the bend-twist coupling characteristic of composites. The anisotropy created by the stacking of layers with optimized angles, taking into account manufacturing constraints, makes it possible to design flexible blades by controlling the stiffness and strength in a desired direction. The shape of the composite propeller, and more precisely the pitch (difference of deflection between the trailing edge and the leading edge), adjusts to the loading induced by the perceived flow, leading to an increased performance over a wider range of operating condition. The designed propeller is based on a reference metallic propeller, the shape will be the same at the design point to allow comparison. The geometry of the composite blades to be manufactured must be calculated with repulsive loads to obtain the unloaded shape, that will deform under pressure and match the reference.
A methodology coupling FEM and CFD models, calculating the hydrodynamic performance, deformations, stresses, and estimated frequencies of the propeller, is developed in this project. Calculation iterations must be performed due to the change in pressure distribution with deformed geometry, and the variation of the shape with pressure loads. Separated models are selected for fluid and structural simulations to limit calculation time, allow different meshing, and perform independent analysis. Sensitivity of element types, materials, and optimization algorithms is carried out with finite element models. An adaptative meshing technique based on error refinement is applied to model the fluid response and was validated across experimental and numerical data. Furthermore, it was observed that few iterations are necessary to obtain convergence of deformations and pressure loads.
The developed methodology will be validated with model and full-scale tests, with measurements to quantify the economic and environmental gains. This work will also be conducted in connection with the applicable norms and reference standards.
This project has received funding from the European Union’s Horizon Research and Innovation Actions, under grant agreement No 101056911, project CoPropel "Composite material technology for next-generation Marine Vessel Propellers.