Evaluation of Torque Transmission Capacity for Centrifugal Compressor Impellers With Pre-Generated Data From Finite Element Analysis

Abstract

Abstract The evaluation of torque transmission capacity for centrifugal compressor impellers can be complicated due to the unique geometric characteristics of the impeller wheels. The existing analytical method for keyless interference fit only works for simple geometries like cylinders. In general, finite element analysis (FEA) simulations are needed to obtain the torque capacity of centrifugal compressor impellers for a specific setup (rotational speed/geometric scale/interference fit rate). However, when the torque capacity needs to be evaluated in multiple working conditions, the time cost of FEA simulations can be an issue if each case is evaluated individually. In this study, a methodology is provided to obtain the torque capacity of centrifugal compressor impellers instantly for any given working conditions with pre-generated data from FEA simulations, especially with scaling of the interference fit rate. If the interference fit rate (ratio of interference fit to diameter) is kept the same as the pre-generated FEA data, the results can be directly scaled by rotational speed and geometric scale factor which is covered by the existing method and not the focus of this study. If the given interference fit rate is different than the setup in pre-generated FEA simulations, then an engineering approximation is used to calculate the contact pressure and torque capacity based on impeller bore deformation. In this methodology, the FEA simulations are performed before knowing the working conditions which can be very useful in many time-sensitive industrial applications.