1990 Fiscal Year Final Research Report Summary
The Development of Energy-Efficient Ships Utilizing Optimization Technique
| Project/Area Number |
63850097
|
|---|
| Research Category |
Grant-in-Aid for Developmental Scientific Research (B).
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
船舶抵抗・運動性能・計画
|
|---|
| Research Institution | Osaka University |
|---|
Principal Investigator |
TANAKA Ichiro Osaka University Fuculty of Engineering Professor, 工学部, 教授 (30028964)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
KAWASHIMA Toshihiko National Research Inst. Fishing Boat and Instrument Research Engineer of Fisheri, 技官
AMAGAI Kiyoshi Hokkaido University Fuculty of Fisheries Associate Professor, 水産学部, 助教授 (50001623)
NAKATO Michio Hirosima University Fuculty of Engineering Professor, 工学部, 教授 (20034324)
IKEHATA Mitsuhisa Yokohama National Univ. Fuculty of Engineering Professor, 工学部, 教授 (10114969)
SUZUKI Toshio Osaka University Fuculty of Engineering Professor, 工学部, 教授 (80029107)
|
|---|
| Project Period (FY) |
1988 – 1990
|
| Keywords | Influence Function / Nonlinear Programming / Frameline Mapping Parameter / Bulb / Fishing Boats / Viscous Resistance / Wave Resistance / Image Processing |
|---|
| Research Abstract |
This summary presents an overview of the research on the development of energy-efficient ships utilizing optimization technique. The main research results sre summarized as follows.
1. A new design tool for reducing the viscous resistance by changing the frameline shape is introduced. In this method, the framelines are represented by conformal mapping parameters and the influence function, which gives the variation of viscous resistance by unit changes of mapping parameters, is explicitly expressed by these parameters. In one application for a full form ship, it is shown that the large bilge radius and the small beam around the stern are required for reducing viscous pressure resistance.
2. The new technique is developed to obtain the influence function numerically for axisymmetric bodies in order to obtain optimum prismatic curve. The influence function gives the relationship between the variation of viscous resistance and small change of radius distribution. The combination of this inf
… More
luence function and a iterative linear programming technique gives an optimum axisymmetric body with minimum viscous resistance under various constraints. In an application under the constraints of constant volume and maximum diameter, it is shown that the low resistance body has a shape witha parallel part whether the initial one has or not.
3. A new high speed displacement ship shape is proposed. It has an airship bulb supported by strut at the bow. The optimum mainhull shape and a bulb shape are obtained by use of SUMT, a kind of nonlinear programming. The calculated wave resistance for 200m ship shows very promising result at the speed of 43 kt. The model test result support the design method.
4. The boundary element method for wave field and the small cross-flow boundary layer theory are applied to obtain the hull form of new fishing boats. The experiments are conducted to check the results of the theory. The experiment implies that the further study for three dimentional separation around buttock slope should be necessary in performing optimization.
5. The new techniques are proposed to obtain the two or three dimensional velocity vectors from the pathline image photograph of the flow field lighted by slit light sheet. The applications for the flow around a simple geometry show very promising results for practical measurements by image processing. Less
|
Research Products
(12 results)
