A radial compressor inlet represents an asymmetric and highly complex flow path, with high potential for flow disturbance. Due to the large computational resources and long lead times required for CFD analysis of such components, this resource has historically been reserved for conceptual or prototype designs. In the production environment, where compressor internals are often customized to a particular application, designers generally rely on geometric analysis of the flowpath. Low priority historically given to centrifugal inlet design is adequately illustrated in “mud etching” of the flow field in a retrofitted radial compressor inlet. An estimate of the potential for efficiency gain through inlet optimization, based on CFD predicted loss coefficient, is presented. It is noted that poor exit flow profiles can negatively impact performance, as well. Ill effects may include efficiency loss in downstream components, mechanical vibration, and compressor control issues. With continual improvement in CFD processing speed, the prospect of applying CFD based optimization techniques to production radial inlet designs becomes more feasible. In this investigation, CFD analysis is performed on an existing radial inlet design and validated with data from a flow visualization test rig. The subject inlet design is subsequently optimized through CFD analysis, with detailed attention being given to the impact of adjusting various geometric characteristics. A number of independent geometric parameters, which are determined to have significant impact on loss coefficient, are condensed into an optimization parameter. This optimization parameter serves as a preliminary indicator of design quality. Alternative brute force design methods are time prohibitive and may not provide the designer with feedback required to effectively alter geometry. Details of the CFD modeling and subsequent validation testing of the baseline inlet design are given. CFD results for a variety of modified inlet designs are presented. An overview of the optimization parameter and its application to a new radial inlet design are also presented. The potential for such an optimization parameter to limit design iteration is illustrated. Although additional refinement is suggested, the subject optimization parameter shows potential to direct the designer away from low efficiency designs.

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