Thesis
The application of the gate rudder system to a small high-speed craft within the offshore wind farm industry
- Creator
- Rights statement
- Awarding institution
- University of Strathclyde
- Date of award
- 2025
- Thesis identifier
- T17243
- Person Identifier (Local)
- 201776287
- Qualification Level
- Qualification Name
- Department, School or Faculty
- Abstract
- The maritime industry has strict targets to achieve zero emissions by 2050. The annual global Green House Gas (GHG) emissions will continue to rise unless there is a change. One solution focuses on reducing a vessel's carbon footprint through increasing fuel efficiency. A series of devices called Energy-Saving Devices (ESDs) focus on just this. A relatively new design of an ESD is the Gate Rudder System (GRS), which consists of two asymmetric rudders fitted parallel to either side of a propeller. The cambered rudder sections work similarly to a propeller duct, producing a beneficial lift force (thrust) and affecting the propeller-hull interaction, which can also be beneficial. So far, the Gate Rudder System has only been fitted to relatively large commercial ships. Sea trials and voyage data have proven that GRS offers superior fuel saving and introduces many other performance benefits. This PhD study aims to apply the GRS to a small high-speed craft, specifically a 20m monohull Crew Transfer Vessel (CTV) with a 24-knot service speed for the worldwide developing wind farm industry. A detailed set of objectives to achieve the above aim is set in nine chapters of the thesis. Within this framework, following the exploration of the existing literature, a baseline conventional twin-screw CTV parent vessel was selected based on the National Physical Laboratory (NPL) series. This vessel was then converted to a single screw by substituting its Conventional Rudder System (CRS) with the Gate Rudder System (GRS). A comprehensive set of numerical experiments using CFD were conducted and validated for towed resistance, open water and self-propulsion simulations. The design decisions made in this research promoted a fair comparison between vessel configurations. The vessel configurations investigated included monohull twin-screw, single-screw vessels with CRS as well as a single screw craft with GRS set at various toe angles. The investigation also included the effect of the rake applied on the Gate Rudder tip at the bottom, further improving the trim characteristics of the hull and the efficiency of the GRS. Out of the single-screw GRS configurations, it was concluded that the GRS with the tip-rake was the superior configuration. When compared to the twin-screw CRS, the single-screw GRS produced lower effective power by 0.37% but required a 4.3% larger delivered power. A cost analysis was made to quantify the potential impact on a real-world CTV, which resulted in an estimated increase of £4.2M in annual profit when compared to a conventional twin-screw monohull CTV. In comparison, a typical conventional catamaran configuration is estimated to generate a £3.3M greater profit. In summary, this research study investigated the application of the GRS on a commercial small high-speed craft for the first time in the open literature, exploring its feasibility on a CTV for the offshore wind farm industry by concentrating on the calm water powering performance of these vessels. While the study revealed the attractive commercial potential of the GRS on such craft, other positive attributes of the GRS, including the powering performance in-service, further support the exploitation of the concept on small high-speed commercial vessels with the aid of further research as recommended in this study.
- Advisor / supervisor
- Atlar, Mehmet
- Resource Type
- DOI
- Embargo Note
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File | 2025-04-16 | Private |