Foil Design

Initiative

The Foil Design JIP aims at achieving advanced knowledge which will assist the early design phase of new concepts of foiling vessels. The research will be focused especially on the performance of the hydrofoils in unsteady conditions.

Background

Hydrofoil technology has been known for decades (the first concept of foiling boat was developed early 1900’s in Italy on Maggiore lake). The real industrial developments for larger ships started in the 50’s and peaked in the 80’s for military applications and passenger transports for relatively short distance. Despite the obvious advantages in terms of improved seakeeping and resistance reduction at high speed, new developments stopped and the current fleet is fading slowly. The reasons of the decline is mainly attributed to high maintenance costs, complexity of propulsion systems and ride control performance.

Recently, top nautical sports revived the interest of foiling and the enthusiasm in general about such technology. The incredible boost in performance for those category of ships has been possible thanks to the use of composite materials, light weight structures and improved ride control. Structural and hydrodynamic simulations capabilities have obviously helped designing such new solutions and to potentially extend the applications to more parties in the maritime sector than in the past.

In the past decades a very complete knowledge has been collected and mostly focused on the performance of hydrofoils in steady state conditions. However, there is still work to be done in terms of dynamic response of hydrofoils in unsteady conditions, particularly in the eventual presence of cavitation and/or ventilation. These aspects are expected to have significant impact in the foil design process. In particular, they are very relevant for dynamic control system design, development of simulation tools and to determine the coupled hydro elastic response of flexible composite foils.

Deliverables

The main deliverables of the research proposed in this JIP are:
  • A data set of practical and contemporary foil design (geometry and performance data as output) which characteristics in steady and unsteady conditions will be available and usable for the set-up of dynamic control strategies.
  • A prediction/design tool for hydrofoils, that includes information on the dynamic response (for hydrodynamic side, including some hydro-elastic effects) . This tool is meant to facilitate early design decisions in the development of future foiling crafts. Focus will be mainly on the type of hydrofoils that require dynamic control.

In this way the time and costs needed to study ships equipped with foils are expected to reduce, as risks can be assessed at a very early stage.

Contact

Contact person photo

Luigi Francesco Minerva

Project Manager Ships

Francisco Miguel Montero

Senior Project Manager

scope of work

  • In first instance the focus will be on fully submerged hydrofoils, requiring dynamic control. Therefore the typical case study will involve a wing, control surfaces such as flaps and one or more support struts.
  • The design methodology will be incorporated in a prediction/design tool. The backbone of the tool will be a simplified theory with an expanded and enhanced applicability thanks to the set of numerical and experimental investigations. These investigations are meant to gather all the required data and fill some of the applicability-gaps of the simplified theory.
  • The set of results will provide also useful information to include basic guidelines, concerning hydro-elastic behaviour and design of the hydrofoil.


The development of the design methodology will be articulated in multiple steps, summarised in the following work packages:
  • Work package 1: fully numerical desk study where the most representative hydrofoil geometries will be identified. A basic simplified method (based on available MARIN’s tools lifting line theory, vortex lattice and/or boundary element method) will be used to perform an initial sensitivity study on the most relevant hydrofoil geometrical parameters.
  • Work package 2: high fidelity investigations by means of numerical (RANS calculations) and experimental (model tests) work on the representative hydrofoil geometries to collect information valid to improve and extend the applicability of the simplified design/prediction tool of the previous work package.
  • Work package 3: Development of prediction/design tool with the integration of the dataset of the investigated hydrofoils. In this work package, a simplified module of the hydro-elastic behaviour of the hydrofoils will be also developed and integrated in the prediction/design tool.

Work package 3: Early design tool

In view of the challenges to be addressed, the project is expected to be of most interest for military applications, transport vessels for a wide range of payloads (from light time sensitive up to heavy goods), for motor yachts and passenger transports design (with top performance in combination with sustainability, efficiency and comfort requirements), for high performance sailing vessels.

This JIP is envisaged to run for 2 years and is open for all interested parties. For further information, don’t hesitate to contact us.