APPLICATION OF NUMERICAL OPTIMIZATION TECHNIQUE WITH THREE DIMENSIONAL NAVIER-STOKES SOLVER TO THE DESIGN OF AN AXIAL-FLOW FAN

摘要

A computer code has been developed to design axial fans by the numerical optimization techniques with three-dimensional Navier-Stokes solver. The steepest descent method and the conjugate gradient method are used to look for the search direction and the golden section method is used for one-dimensional search. To solve the constrained optimization problem, sequential unconstrained minimization technique, SUMT, is used with imposed quadratic extended interior penalty function. In the optimization of two-dimensional cascade design, the ratio of drag coefficient to lift coefficient, is minimized by design variables such as maximum thickness, maximum ordi-nate of camber and chordwise position of maximum ordinate. In the optimization of three-dimensional axial-flow fan, the efficiency is maximized by the design variables related to the sweep angle.