1-7 非線形計画法による船型最適化の試み (第4報) : 件流と粘性抵抗を考慮した船体後半部形状の改良

抄録

This paper presents an application of Computational Fluid Dynamics to ship hull optimization, which is based on the nonlinear programming approach developed by Hamasaki et al. The hull forms are first expressed by the offsets table and variation function using the B-spline functions, whose coefficients are used as the design variables. Then the fully-elliptic Reynolds-averaged Navier-Stokes and continuity equations are solved with zero-equation turbulence model to provide viscous resistance and stern flow information. The aft part of hull is optimized so as to minimize the viscous resistance and the value of wake at the top of propeller disc. The affine scaling interior method is used in the present multi-objective optimization procedure. The present iterative optimization procedure yields steady convergence of the solutions and appeared to be capable for practical ship form design. An overview is given of the present numerical method, and results are presented and discussed for the Series60 CB=0.8 as an initial form including comparison with available experimental data. In addition, requirements for improvements of the present approach are described regarding accuracy in computing the sensitivity coefficients.