Another technology that shall be employed during the course of the RETROFIT55 project is the Passive Air Lubrication System (PALS), developed by Armada Technologies Limited.
The PALS has obtained a proof of concept in the HYKAT Cavitation tunnel, HSVA, in Hamburg showing that an air-water mixture could be reliably produced without the need for external air compressor(s). Based on the previous achievements, further research and development will be undertaken in order to quantify and optimize the achievable drag reduction across different ship types, drafts and ship motion/ sea states.
The main objectives are:
· determining the optimal design and layout of the full PALS,
· optimizing the system to deliver 8-12 per cent fuel saving (optimizing the venturi component)
· evaluating risks and devising mitigation plans,
· obtaining classification Approval in Principle (AIP), and installation and operation requirements.
The objectives will be met through CFD simulations, tank testing at different conditions and arrangements, and a thorough risk assessment.
Armada will test a scaled model of PALS in Consiglio Nazionale delle Ricerche (CNR) – Institute of Marine Engineering towing tank facility. The air-water mixture will be reproduced, at scale, through the use of a micro-bubble generator and delivered beneath the model hull through scaled models of the PALS injectors installed into the ship model. The CFD studies will enable the team to establish a scaling technique to project an accurate drag reduction based on the vessel’s hull and operation conditions.
During the design and optimization process, close collaboration will be maintained with partnering classification society to ensure that the system is safe for operation at sea and mitigate risks. Most classification societies have clear sets of regulations for ALS, which will substantially reduce any risk regarding the safety of Armada’s system.
