Complex modal balancing of flexible rotors including residual bow

A balancing procedure utilizing the Complex Modal Method is presented for linear flexible rotor dynamic systems including the effect of residual shaft bow. The method does not require trial runs; however, a valid mathematical model of the system dynamics is required to obtain the system's modal parameters, which are used to relate the balance corrections to measured responses. Several balancing strategies based on the extension of previous work are suggested for single-speed balancing. Two applications are presented: 1) a gas turbine system with computergenerated response data, and 2) an operating steam turbine-generator system.