Developments In Hydrodynamic Force Models For Velocity Prediction Programs

Claughton, Andrew; Oliver, James

doi:10.3940/rina.tmy.2003.09

Cited by 5 publications

(3 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Nonetheless, Dijkstra's original algorithm exclusively accounted for static edge weights (Dijkstra, 1959). When dynamic edge weights are present, Orda and Rom (1990) demonstrated that, in general, there are no computationally efficient algorithms.…”

Section: Shortest-path Algorithmsmentioning

confidence: 99%

See 1 more Smart Citation

VISIR-2: ship weather routing in Python

Mannarini,

Salinas,

Carelli

et al. 2024

Geosci. Model Dev.

View full text Add to dashboard Cite

Abstract. Ship weather routing, which involves suggesting low-emission routes, holds potential for contributing to the decarbonisation of maritime transport. However, including because of a lack of readily deployable open-source and open-language computational models, its quantitative impact has been explored only to a limited extent. As a response, the graph-search VISIR (discoVerIng Safe and effIcient Routes) model has been refactored in Python, incorporating novel features. For motor vessels, the angle of attack of waves has been considered, while for sailboats the combined effects of wind and sea currents are now accounted for. The velocity composition with currents has been refined, now encompassing leeway as well. Provided that the performance curve is available, no restrictions are imposed on the vessel type. A cartographic projection has been introduced. The graph edges are quickly screened for coast intersection via a K-dimensional tree. A least-CO2 algorithm in the presence of dynamic graph edge weights has been implemented and validated, proving a quasi-linear computational performance. The software suite's modularity has been significantly improved, alongside a thorough validation against various benchmarks. For the visualisation of the dynamic environmental fields along the route, isochrone-bounded sectors have been introduced. The resulting VISIR-2 model has been employed in numerical experiments within the Mediterranean Sea for the entirety of 2022, utilising meteo-oceanographic analysis fields. For a 125 m long ferry, the percentage saving of overall CO2 expenditure follows a bi-exponential distribution. Routes with a carbon dioxide saving of at least 2 % with respect to the least-distance route were found for prevailing beam or head seas. Two-digit savings, up to 49 %, were possible for about 10 d in a year. In the case of an 11 m sailboat, time savings increased with the extent of path elongation, particularly during upwind sailing. The sailboat's routes were made approximately 2.4 % faster due to optimisation, with the potential for an additional 0.8 % in savings by factoring in currents. VISIR-2 serves as an integrative model, uniting expertise from meteorology, oceanography, ocean engineering, and computer science, to evaluate the influence of ship routing on decarbonisation efforts within the shipping industry.

show abstract

Section: Shortest-path Algorithmsmentioning

confidence: 99%

“…The modelling of the sailboat STW was carried out by means of the WinDesign velocity prediction program (VPP). The tool was documented in Claughton (1999Claughton ( , 2003 and references therein. The VPP is able to perform a fourdegrees-of-freedom analysis, taking into account a wide range of semi-empirical hydrodynamic and aerodynamic models.…”

Section: Sailboatmentioning

confidence: 99%

VISIR-2: ship weather routing in Python

Mannarini,

Salinas,

Carelli

et al. 2024

Geosci. Model Dev.

View full text Add to dashboard Cite

show abstract

“…The modelling of the sailboat STW was carried out by means of the WinDesign Velocity Prediction Program (VPP). The tool was documented in Claughton (1999Claughton ( , 2003 and references therein. The VPP is able to perform a four degrees of freedom analysis, taking into account a wide range of semi-empirical hydrodynamic and aerodynamic models.…”

Section: Sailboatmentioning

confidence: 99%

VISIR-2: ship weather routing in Python

Mannarini,

Salinas,

Carelli

et al. 2023

Preprint

View full text Add to dashboard Cite

Abstract. Ship weather routing, which involves suggesting low-emission routes, holds potential for contributing to the decarbonisation of maritime transport. However, its quantitative impact has been explored only to a limited extent, also for a lack of readily deployable open-source and open-language computational models. As a response, the VISIR model has been refactored in Python, incorporating new features. The velocity composition with currents has been refined, now encompassing leeway as well. For motor vessels, the angle of attack of waves has been considered, while sailboats now account for the combined effects of wind and sea currents. A least-CO2 algorithm in presence of dynamic graph edge weights has been implemented and validated, proving a quasi-linear computational performance which outperforms VISIR-1. The software suite’s modularity has been significantly improved, alongside a thorough validation against arious benchmarks. The resulting VISIR-2 model has been employed in numerical experiments within the Mediterranean Sea for the entire 2022, utilising meteo-oceanographic analysis fields. For a 125-meter-long ferry, the distribution of carbon dioxide savings follows a bi-exponential distribution. Two-digit CO2 savings were possible for more than ten days in a year. Largest savings were achieved in avoiding upwind sailing and using the lowest engine load. In the case of an 11-meter sailboat, time savings increase with the extent of path elongation, particularly during upwind sailing. The sailboat’s routes were approximately 3 % shorter thanks to optimisation, and there was potential for additional savings when favourable currents were in play. The impact of leeway was minor, but disregarding it would result in a systematic underestimation of route durations. VISIR-2 is a collaborative model with the capacity to harness knowledge from oceanography, ocean engineering, and computer science, to contribute to the decarbonisation efforts in the shipping industry.

show abstract

Low-aspect ratio appendages for wind-assisted ships

Kolk¹,

Akkerman

Keuning

et al. 2021

J Mar Sci Technol

View full text Add to dashboard Cite

Wind propulsion for commercial ships has been identified as a key component in the energy transition for the maritime industry. The sailing hybrid ship will operate with leeway (drift) angles to produce a lateral force known as sideforce, for steady operation under sail. In this paper, experimental results for the sailing performance of ships fitted with bilge keel appendages are presented. Systematic variations in appendage height, length, and position were tested, including several special cases (multiple bilge keels). The appendage typology is shown to mitigate the strong ‘destabilizing’ yaw moment that is characteristic of wind-assisted commercial vessels and to promote the non-linear sideforce component. The working principal for bilge keels—promotion of flow separation—can be employed to specify the separation location for components of the vessel vortex wake to improve the sailing performance of the ship.

show abstract

Developments In Hydrodynamic Force Models For Velocity Prediction Programs

Cited by 5 publications

References 0 publications

VISIR-2: ship weather routing in Python

VISIR-2: ship weather routing in Python

VISIR-2: ship weather routing in Python

Low-aspect ratio appendages for wind-assisted ships

Contact Info

Product

Resources

About