A Preliminary Evaluation Method For Fan Blade Rubbing Stability Based On Finite Element Analysis

A tighter fan blade-casing clearance is desired to obtain better aerodynamic efficiency and stability in the aero engine. But the risk of blade-casing rubbing will increase and lead to unexpected blade vibrations or damage. Unstable rubbing will damage the engine structure and should be avoided. Fan blade rubbing stability must be evaluated during the initial design phase. At present, many scholars use numerical analysis research methods, this method involves many parameters, and the analysis process is complex. This paper adopts a simple and relative method to evaluate the fan blade rubbing stability. The rubbing loads are applied on the tip of the fan blade and the deformation of the tip nodes are obtained. By comparing the rubbing force and the amplitude of the tip deformation, a relative rubbing stability of different design of fan blade could be achieved. The results of this method are compared with that calculated by delayed differential equation. The agreement of these results shows the validity of this method.