SR231「中型肥形船の総合的運航性能の研究」 要約
SHIP RESEARCH PANEL 231
A Comprehensive Study on Service Performance of a Series of Shallow Draft Medium Sized Full Ships
Summary
To provide the technical fundamentals of ship form design of a medium sized shallow draft single screw full ship with much improved aspects of service performance, namely economy, safety and reliability, and quality, extensive investigations were conducted on a series of full ship forms on the basis of both model experiments and computational studies. The marked features of these full ship forms are characterized by both higher fullness of after body and larger breadth draft ratio than those of the medium sized full ships presently operating. The ship's performance investigated includes propulsive performance, property of flow around propeller, maneuverability, sea-keeping quality, propeller performance containing pressure fluctuations induced by a cavitating propeller. Among the investigations, the propulsive performance in sea way was examined by statistical prediction of resistance increase in the short crested irregular waves specified as the reference sea condition. The maneuvering motion simulation based of the mathematical model (MMG model) was made to evaluate maneuverability of these full ships, refering the IMO interim standards for ship manuverability. Availability of the computational prediction methods based on the fluid dynamics for design of full ship forms was assessed through comparative studies with the result of model experiments. Summarizing the results of investigations made above, some practical guide lines for design of shallow draft medium sized full ship form with peculiar features above were proposed regarding decision of ship form parameters, such as breadth draft ratio, fullness and frame line of after body, and application of the computational fluid dynamics to prediction of propulsive performance.
Major items of the investigations are (a) design of a series of shallow draft single screw full ship forms with wide variation of principal dimensions on the basis of information obtained by survey on the presently existing medium sized full ships, (b) model experiments on ships and propellers regarding the hydrodynamic ship's performance, (c) evaluation of the model test results compared with numerical estimation of each element of ship's performance by use of the presently available computational methods based on the fluid dynamics, (d) numerical study on propulsive performance in irregular waves, and (e) assessment of the service performance composed of major aspects of economy, safety and quality, summarizing the results of examinations.
