An Investigation On Dynamic Characteristics Of Gas Turbine Rod-Fastening Rotor

With the development of gas turbine techniques, disc-type rod fasteningrotor is widely used in heavy duty gas turbine. Dynamic characteristics of rodfastening rotor，which is core component，decides performance of gas turbine.The main structural characteristic of central rod fastening rotor is that a rotoris not continuous, leading to different dynamic behaviors and studyingapproach from integrated rotor. Consequently it is necessary to make afurther study on the issue.On the framework of Riccati Transfer Matrix Method, analysis approachfor dynamic characteristics of non-continuous rod fastening rotor is firstlydiscussed in this paper. With regard to the Hirth serration structure, takingaccount to the contact effects between impellers, contact stiffness is deeplystudied through3D finite element method. And then, with regard to structurefeature of a certain central rod-fastening rotor of F-class gas turbine, rotorsystem is discretized and simplified, bearing characteristics are calculated.Consequently, computation model of the rotor-bearing system is established.At last, by means of developed computer program, some numerical results ofdynamic characteristics such as critical speeds of lateral vibration, mode shapes and unbalance response have been obtained. Critical speeds are ingood agreement with test measurement result, which implies that thenumerical results are accurate and the computation model is valid.The above investigation solve the problem how to evaluate dynamiccharacteristics of rod fastening rotor accurately through Transfer MatrixMethod, which provides reference for disc-type rod fastening rotor-bearingsystem in engineering practice both in design and operation.