Insights into the flow within the well dock of a mothership during feeder vessel docking manoeuvres
Johnson, NTM and MacFarlane, GJ and Duffy, JT and Penesis, I and Ballantyne, RJ, Insights into the flow within the well dock of a mothership during feeder vessel docking manoeuvres, Transactions of the Royal Institution of Naval Architects Part A: International Journal of Maritime Engineering, 162 pp. A1-A14. ISSN 1479-8751 (2020) [Refereed Article]
An experimental campaign has been undertaken to explore the flow around a feeder vessel as it manoeuvres in and out of the well dock of a mothership. The parent hulls for this study are drawn from the floating harbour transhipper concept created by Sea Transport Corporation. Laser measurement techniques have been employed to analyse the flow field within the well dock while the feeder vessel both enters and departs. For the Master of the feeder vessel to safely perform these manoeuvres, the complex flows resulting from the highly confined nature of the well dock concept need to be understood and potentially mitigated. It is shown that the inclusion of vents in the well dock can significantly influence the flow and that their effectiveness is determined by the size of the vents. This study further progresses the authors' recent work on the same novel concept where the confined water effect of the well dock and inclusion of vents is quantified for both the seakeeping behaviour and the docking/departure performance. It is concluded that the use of vents is very beneficial when a feeder vessel docks or departs the well dock, however a compromise on the vent size must be reached in order to reduce adverse effects on feeder vessel motions when docked and exposed to a seaway. It is likely that the optimum solution, that covers all operational parameters, only requires the inclusion of relatively small vents.