Experimental modal analysis of compressor rotor blades.

Prediction of dynamic characteristics of turbomachinery components (such as compressor & turbine rotors) of a gas turbine engine is very important to ensure safe operation. The rotor blades shall be designed such that, their natural frequencies do not coincide with possible excitation sources in the engine in order to avoid resonance. During the design phase, natural frequencies and associated mode shapes need to be predicted through computational methods. After the component is made, it is also essential to measure its dynamic characteristics through experimental modal analysis. In this study, a centrifugal compressor rotor of a small gas turbine engine is considered. Detailed numerical modal analysis was performed using ANSYS FEM software package. By the OROS modal analysis arrangement, the tentative modal analysis was carried out. The analysis was carryout at Propulsion Division, National Aerospace Laboratories. The results derived from the experimental analysis were compared with numerical analysis and were found to be a good agreement. The frequencies of blades have enough separation margin from the possible excitation frequencies. [ABSTRACT FROM AUTHOR]