SHAPE OPTIMIZATION OF CUTOFF IN A MULTIBLADE FAN/SCROLL SYSTEM USING RESPONSE SURFACE METHODOLOGY

This article presents a new method that overcomes three-dimensional effects by using two-dimensional computational fluid dynamics (CFD) and response surface methodology (RSM). The method is applied to shape optimization of cutoff. The distributions of velocity and pressure obtained by two-dimensional CFD analysis are compared with those of three-dimensional CFD analysis and experimental results. RSM with central composite designs is used to obtain an approximated volume flow rate in terms of the angle and curvature radius of cutoff. The optimal angle and radius of cutoff are determined as 72.4° and 0.092 times the outer diameter of the impeller, respectively.