TUD21 Propeller and Rudder Performance in Wind Assisted Ship Propulsion

Summary of the project

Wind assisted ship propulsion technologies can help to significantly reduce the emissions in the shipping industry. While developing novel wind propulsion devices, it is of equal importance to make adaptations to the waterborne propulsion and steering systems to maximize fuel savings and balance the generated aerodynamic forces. Traditional propeller designs focus on efficiency in steady conditions, but wind-assisted ships require propellers that perform well across a range of conditions due to varying wind contributions. This adds new challenges to the design process of marine propellers.

To investigate the forces on the propeller-rudder system under off-design conditions like oblique inflow and variable advance ratios state of the art numerical simulations and high fidelity experimental data will be used. Simulations will analyse how drift angles and varying advance ratios affect wake structure and inflow straightening behind the propeller. Different propeller geometries and configurations will be assessed for thrust, torque, and cavitation risk and validated with towing tank experiments.

The numerical and experimental data will be used to develop a physics informed model for predicting propeller and rudder performance under off-design conditions. This will significantly improve the accuracy of the performance assessment of wind-assisted ships, contributing to more efficient and sustainable maritime transport.

Goal of the project

The project aims to systematically investigate the forces acting on the propeller rudder system of sail-assisted ships under various operating conditions. It focuses on assessing performance with oblique inflow and variable advance ratios, ultimately developing a physics-informed model to enhance performance prediction of an integrated aft-ship, propeller, and rudder system in wind-assisted conditions.

This research significantly advances zero emission shipping by optimizing the interaction between wind-assisted propulsion systems and traditional waterborne propulsion. Enhancing the efficiency of the propeller and rudder in diverse wind assisted scenarios ensures that ships can maintain optimal performance at minimal fuel use, regardless of wind variability.

Insights will apply to new ship designs and retrofitting existing vessels with wind assisted systems, promoting a faster transition towards zero emission operations.

Motivation

The project is motivated by the target of working towards a zero-emission shipping industry. As decided by the international maritime Organization (IMO) the shipping industry should reduce its Co2 emissions in 2050 to a maximum of 50 percent of the level in 2008. To meet these criteria, ships need to be more energy efficient preferably using sustainable sources of energy such as wind in the near future. With clearly defined stepwise emission reductions until 2050 the transition towards zero emission shipping hast to start now and cannot be postponed. In hindsight of this the shipping industry has to further invest in the development of innovative zero emission propulsion concepts such as wind assisted ship propulsion.

Innovativeness

The current state-of-the-art in ship propeller and rudder performance analysis focuses on straight course sailing at constant speeds. However, this approach does not account for steady drift angles and variable advance ratios, which are becoming common with the rise of wind-assisted ships. Traditional analyses lack a comprehensive understanding of these off-design conditions, now permanent in wind-assisted propulsion. With the increasing installation of wind propulsion devices on various ship types, there is a growing need for fundamental knowledge about the influence of these conditions on different aft ship geometries and propeller configurations. Understanding these interactions is crucial for optimizing the overall efficiency of hybrid propulsion systems that combine novel wind devices with traditional waterborne propulsors.

This project aims to advance beyond the current state-of-the-art by systematically analyzing propeller and rudder performance under steady drift angles and variable advance ratios. Utilizing state-of-the-art numerical tools, it will investigate these conditions across different ship designs, identifying challenges and impacts on future wind-assisted ships’ propeller and rudder designs. A significant innovation of this project is the production of high-fidelity measurements to validate propeller rudder interactions under these new conditions. Existing computational tools, while advanced, lack sufficient validation for scenarios involving steady drift angles and variable

advance ratios. By conducting model-scale experiments, the project will generate essential experimental data to bridge this validation gap. Furthermore, the project will develop a data-driven model using the comprehensive dataset from its analyses. This model will accurately predict propeller and rudder performance within the defined design space, enhancing the efficiency of the design process.

This project’s innovative approach addresses critical gaps in current methodologies, combining advanced numerical tools, experimental validation, and data-driven modeling. By doing so, it significantly advances the understanding and prediction of propeller and rudder performance in wind-assisted ships, leading to more efficient hybrid propulsion systems.

Valorisation

Duration project

Start date: 11/09/2024

End date: 11/09/2028