Application of similitude theory in modified design of a fan

A modified design of a fan was described, on the basis of enough performance and flow field analysis of original fan, in order to satisfy the more thrust requirement of a turbo-fan engine. The modified design method was: the design tool was “a general blading design system and its application for axial/centrifugal compressor”. According to the similitude theory, at the precondition of the equivalence of converse mass flow and converse revolution speed at the second stage inlet, the increase of the mass flow was growing with the pressure ratio. By CFD computation and analysis, all the performances met the requirement and the design result was perfect. The results show that as the speed of the fan increases 1.1 percent, the mass flow increases 7.1 percent, the pressure ratio increases 7.4 percent, the efficiency increases 2.9 percent, and the stall marge increases 0.8 percent. Analysis and valuation of the performance and matching characteristic indicate that this design can satisfy the more thrust requirement of the turbo-fan engine.