Structural analysis of continuous fiber wound composite impellers of a multistage high-speed counter rotating axial compressor for compressing water vapor (R-718) as refrigerant using Finite Element Analysis

• Three different fiber/epoxy composite impellers investigated.
• FEM model to accurately model filament wound impellers is developed.
• Carbon/Epoxy impeller is the strongest according to static stress analysis.
• Campbell plots were generated to get an overview of the impeller vibration characteristics around operating conditions.

In this study a low cost, light weight and high performance novel filament wound axial impeller of a multistage counter rotating axial compressor for compressing water vapor (R718) as refrigerant is investigated structurally. Three different fiber types were chosen as suitable materials for this study (Kevlar-49, S-Glass & Carbon fiber) with a standard epoxy resin for the composite matrix. Through means of FEA (Finite Element Analysis) method; stress, displacement and vibration analysis procedure is developed to assess the maximum stress, change in dimensions and natural frequencies of these impellers under constant operating conditions. The finite element modeling was performed on commercially available software Abaqus. The modeling technique is explained in detail with regards to static structural and dynamic analysis of the impellers. Operating stresses, maximum shroud deflections, modal frequencies and effect of centrifugal stiffening is calculated and discussed in detail along with Campbell plots for each fiber material type. The study provides critical details about the structural behavior of the impellers and aims to provide a methodology to the compressor designer to support his decision in choosing the type of impeller and designing the housing.