A computational iterative design method for bend-twist deformation in composite ship propeller blades for thrusters

Abstract

This study investigates the feasibility of utilising common composite material layup techniques in ship propeller blade design to achieve an automatic pitch adjustment through bending-induced twist deformation. A comprehensive design approach, including various reinforcement materials and arrangements, was employed to attain the desired foil pitching, while minimising other undesirable deformation modes. The design process involved iterative computational analysis using finite element analysis and a deformation mode analysis based on foil shape parameters. The research showed that the proposed design approach effectively found options to improve the desired foil parameter pitch, while minimising undesirable deformation modes such as blade deflection and foil shape change. Furthermore, the proposed blade design was tested in thruster steering operational conditions and was found to have a pitch change well matched, potentially countering some changes in fluid flow. When compared to Kumar and Wurm’s design, which only focused on the angular orientation of glass reinforcement, the proposed design was found to outperform the twisting by achieving the same twist for a blade half the length. This study provides valuable insights into the utilisation of composite materials in ship propeller design and highlights the potential for further improvement through a composite engineering design approach.

Designing Composite Adaptive Propeller Blades with Passive Bend–Twist Deformation for Periodic-Load Variations Using Multiple Design Concepts

“…While an extraordinary feat, such algorithms are only optimised within the considered parameters and for the considered desirable outcome. However, how one can arrange various materials to make a composite propeller is mainly limited by the materials, blade geometry, imagination and manufacturability [ 8 ]. The vast number of factors that need to be considered makes the adaptive propeller-blade design process complex.…”

“…The finite element analysis (FEA) used in this paper is performed with the FEA software Abaqus 2017 by Systema Dassaults [ 36 ]. An Abaqus FEA methodology is applied based on FEA methods that have been explored and experimentally verified in previous publications [ 8 , 27 , 28 , 29 , 37 , 38 ]. The paper that explored the experimental verification of the FEA method on a composite propeller was previously published in Polymers [ 38 ].…”

“…After exploring the design concepts of the generalized NACA model, the concepts are applied to the bend–twist propeller-blade design for a typical metal propeller-blade geometry. This propeller blade is a commercial metal-blade design that has been used in the published literature [ 8 , 27 , 28 , 37 ]. The blade design has several unique propeller geometry features, such as a significant blade skew, a varying sectional foil profile along the blades span and a propeller radius of 650 mm.…”

“…The deformation characteristics in all blade models are evaluated by tracking the foil-shaped cross-sections throughout the blade span during loading [ 8 , 27 , 28 , 29 ]. The parameters tracked in this study were blade deflection, blade twist, bend–twist (coefficient of twist per bending deflection) and camber (foil shape indicator).…”

“…For the final propeller-blade design, the goal was to obtain a combination of as much bend–twist as possible while aiming for a specific deformation characteristic, i.e., a desirable twist causing sufficient blade pitch change between the minimally and maximally loaded blade in a specific periodic-load variation. The periodic-load case investigated in this paper has been used in previous studies [ 8 , 27 , 28 ]. It has been shown that when the thruster is rotated to an 8° steering angle relative to the vessel’s travel direction to change the heading, the periodic-load variation almost doubles the total blade load between the minimum and maximum load [ 8 , 27 , 35 ].…”