FATIGUE ANALYSIS AND DESIGN OF DIFFERENT COMPRESSOR ROTOR BLADE OF AN ORPHEUS ENGINE

This paper "Fatigue Analysis and Design of Different Compressor Rotor Blade of an Orpheus Engine" is carried out in blade shop department, Engine Division, Compressor rotor blades are made up of aluminium and titanium based super alloys, is mounted on the rotor disc of compressor assembly unit. The purpose of compressor rotor is to raise the pressure of incoming air to have an efficient combustion in the combustion chamber to generate enough power to propel the aircraft. Moreover the Orpheus engine speed between 5000 to 7000 rpm is the critical rpm which is due to the 2 nd and 3 rd stage of rotors. It is therefore becomes mandatory to carry out fatigue testing on every production batch of indigenously developed forging of rotor-2 and rotor-3 blade before fitment on to the engine. Presently the rate of rejection during fatigue testing is up to 70%. The proposed paper is an attempt to reduce the rejection rate of compressor rotor blades stage-2 and 3 comparing the results through structural analysis procedures may help us to provide suggestions for increasing the fatigue life of the rotor blades. As a result this paper comes up with recommendations to improve the fatigue life of blades by improving the surface finish of blade by introduction of manual buffing operation on blade aerofoil after glass bead preening. On implementation the rejection rate is expected to be reduced to less than 5%. As a consequence we see timely