Rotordynamic Analysis of Vertical Turbine Pump

Abstract

Rotordynamics is a specialized branch of applied mechanics which concerns the behaviour of rotating structures. Since the past decade, the study about rotordynamics has gained more importance within pump industries and more specifically vertical turbine pumps. The main reason is vertical turbine pump has a slenderer rotating structure as compared to other centrifugal pumps with different cross-sections and different rotors which makes it a complex dynamic system. When designing rotors of high-speed turbo types of machinery, it is prime importance to consider rotordynamics characteristics in to account. By taking into account these characteristics at the design stage may prevent the rotating system from several catastrophic failures. These rotordynamic characteristics can be determined with either the Finite element method or Analytically with the help of the Numerical method. The design evaluation criteria of standards like API, HI will help qualify the vertical turbine pump's shaft design. The aim of this thesis is to establish the methodology for Rotordynamic analysis for vertical turbine pump. This work helps in understanding the mechanics behind rotordynamics like effect of gyroscopic couple in the system. Transfer matrix method (TMM) is used to solve simple rotordynamic model like Jeffcott rotor for easy understanding. This thesis developed a procedure for rotordynamic analysis of vertical turbine pump using ANSYS APDL code and validated with the experimental results found by various researchers. This work will consider Lateral rotordynamic analysis and Torsional Rotordynamic analysis. Because vertical turbine pump has axial thrust bearing, longitudinal rotordynamic analysis is not considered in this work.