3-D optimization of design variables in x-, y- and z-directions of transformer tank shield model

By using the automatic 3-D mesh generation technique using hexahedral elements, which is applicable when design variables are changed in x-, y- and z-directions, a transformer tank shield model is optimized. The volume of tank shield can be considerably reduced by using the Rosenbrock's method (RBM) compared with the previous result having design variables in one direction. It is shown that the determination of initial values for RBM using the experimental design method (EDM) is indispensable for the practical application of the optimization method to obtain a desired result within an acceptable CPU time.