A Study on Layout Optimization Problem of 2-D Tandem Hydrofoils under Free Surface

Abstract

This paper presents a study on layout optimization problem of tow-dimensional tandem hydrofoils under free surface. Numerical method is based on nonlinear programming approach, where the local linear solution is obtained by affin scaling interior method. Source-circulation panel method is used to compute wave-making resistance, which is minimized in the optimization procedure. The present method is capable for unlimited number of wings; however, in the present paper, results are presented for four-wing problem, i.e., each of fore and aft. wing systems is composed of main wing and Fowler flap, whose relative location and attack angle are used as design parameters. It is shown in the results that the hydrodynamic forces acting on main wing of aft. wing system has the largest influence on lift and drag forces of whole system, and also the initial design parameters must correctly be given in order to obtain non-trivial optimized solution.