Material Selection for a Turbocharger Centrifugal Compressor Wheel 2020-01-5066

This paper aims at providing an analysis for the proper selection of the materials of the turbocharger’s impellers that fully satisfy the essential operation requirements in terms of attaining the highest volumetric efficiency (lowest possible tip clearance) and withstanding stresses at varying loading conditions. For that purpose, considerations are given to investigation of the resulting stresses, strains, and displacements resulting from the on-wheel centrifugal, aerodynamic, and thermal loading conditions. The study is based on both a mathematical and a finite element analysis (FEA). Fatigue life assessment of the compressor wheel is also investigated in an attempt to determine its durability (lifetime assessment) by comparing the stress analysis results obtained for three different aluminum alloys, namely (AA 2618, Ti-6Al-4V, and C355). Based on the results analysis, Ti-6Al-4V operates for infinite lifetime showing the lowest displacement. Thus, it is suitable for critical applications like marine, petroleum industries, and military equipment. Aluminum alloy C355 shows nearly infinite lifetime operation and the highest value of displacement, making it suitable for predetermined fixed loads. Finally, aluminum alloy AA2618 will operate for a limited lifetime with a relatively low displacement, which makes it recommended for varying loading conditions as in heavy engine equipment.