Statistically Study on Speed Loss in wind and Waves

1989 Fiscal Year Final Research Report Summary

• Project/Area Number: 62460146
• Research Category: Grant-in-Aid for General Scientific Research (B)
• Allocation Type: Single-year Grants
• Research Field: 船舶抵抗・運動性能・計画
• Research Institution: Yokohama National University
• Principal Investigator: TAKARADA Naonosuke Yokohama Nat. Univ. Fac. of Eng. Professor, 工学部, 教授 (00188103)
• Co-Investigator(Kenkyū-buntansha): INOUE Yoshiyuki Yokohama Nat. Univ. Fac. of Eng. Professor, 工学部, 教授 (60126373)
• Project Period (FY): 1987 – 1989
• Keywords: added resistance / speed loss / unmaneuverability / propulsive engine power

Research Abstract

The influence of shipform characteristics on resistance increase and speed loss In wind and waves are investigated. The estimation are carried out for 4 kinds of ships, which are general cargo ships, bulk carriers, pure car carriers and container ships. The results of these analysis shows that huge ships with low service speed have a trend of causing a great deal of speed loss in wind and waves.
Therefore, the added resistance In waves at low forward speed acting on a huge bulk carrier is further investigated by using three dimensional source technique with forward. The numerical results are in good agreement with measured one.
Finally, propulsive engine power ratios to displacement of huge bulk carriers are investigated and probabilities of unmaneuverability due to heavy seas are estimated in case of North America - Japan route. As the results, the huge bulk carrlers which have low propulsive engine Power ratio to the displacement are considered as the lowest power, from the viewpoint of probability of unmaneuverability due to heavy seas .