Manoeuvring behaviour of push convoys: sub report 8. Additional fast time validation of Class Va and Vb vessels
Vos, S.; Delefortrie, G.; Mostaert, F. (2018). Manoeuvring behaviour of push convoys: sub report 8. Additional fast time validation of Class Va and Vb vessels. Versie 2.0. FHR reports, 15_001_8. Flanders Hydraulics Research: Antwerp. VIII, 28 + 20 p. app. pp. Part of: FHR reports. Flanders Hydraulics Research: Antwerp, more |
Available in | Authors | | Document type: Project report
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Keywords | Harbours and waterways > Manoeuvring behaviour > Open water Simulation Simulations Validation
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Abstract | This report describes the validation process of the simulation vessels Peche Melba and Dame Blanche which are the simulation names for the push convoys of (CEMT-)class Va and class Vb. The vessels consist of one or two barges with several loading conditions. Mathematical models were developed for a combination of empty (E, draft 3 m) and full (F, draft 4 m) barges.The validation in the report is based on results of standard manoeuvres, performed with fast-time simulations. These simulations have been extended with unsteady turning manoeuvres. Skippers often have to manoeuvre in confined areas. During an approach of a lock or the execution of a turning manoeuvre in a swinging area, the manoeuvring model is often used beyond quadrant I. Sailing ahead with a negative thrust (propeller that runs astern) or sailing astern with a positive thrust are quite common. Because of that it was decided to perform turning manoeuvres in unsteady conditions. Normally a turning manoeuvre is started at a self-propulsion point. Because the speeds are rather small while approaching a lock or executing a turning manoeuvre, small initial negative and positive speeds have been applied for the turning manoeuvres. In several conditions the rate of turn during these unsteady turning manoeuvres wasn’t smooth. A drop of the rate of turn could be noticed. Starting with a negative speed, in some conditions it was not possible to reach a positive speed with the larger rudder angles. This was solved by reducing coefficient FX. By reducing NP, the drop issue of the rate of turn was improved. Additional to the reduction of NP, a few outliers were removed in the tables YPBetaTabel and YPGammaTabel. |
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