An Impeller Dynamic Risk Assessment Toolkit

A standardized and cost-effective risk assessment toolkit is described in this paper to comprehensively analyze centrifugal compressor impellers under steady and dynamic loads. The first step in this process occurs in the proposal stage where the gas loading levels are appraised using a preliminary screening computer program. The application engineers execute the product configuration program for each proposal that invokes the screening program. All designs are screened for steady gas bending stress levels for each client-required operating point. An additional dynamic audit is performed if these stresses are above a given threshold level. The alternating loads are derived from upstream and downstream flowpath disturbances. Natural vibration modes that need to be avoided are evaluated using the SAFE diagram and harmonic response analysis, followed by automated results postprocessing. The overall minimum factor of safety is determined for all impeller model locations and known excitations using a fully automated process. The use of this advanced analysis approach, which has been developed using a blend of automated computer simulation and broad experience base, results in greater reliability, profitability, and reduced risk for both client and manufacturer. Practical real-world examples of impellers analyzed using this approach will be presented in this paper.