An Arnoldi Approach for Generation of Reduced-Order Models for Turbomachinery. Submitted, Computers and Fluids

A linear reducedorder aerodynamic model is developed for aeroelastic analysis of turbo machines The basis vectors are constructed using a block Arnoldi method Although the model is cast in the time domain in statespace form the spatial periodicity of the problem is exploited in the frequency domain to obtain these vectors eciently The frequency do main proper orthogonal decomposition is identied as a special case of the Arnoldi method The aerodynamic model is coupled with a simple structural model that has two degrees of freedom for each blade The technique is applicable to viscous and threedimensional problems as well as multistage problems with inlet and exit disturbance ows although here results are presented for twodimensional inviscid ow through a twentyblade single stage rotor In this case the number of states of the model is on the order of ten per blade passage making it appropriate for control applications With the current trend towards increased operating speeds and more exible blading aeroe lasticity has become a critical consideration in the design of compressors Understandin