Considerations for Using Additive Manufacturing Technology in Centrifugal Compressor Research

Abstract

An additive manufactured (AM) vaned diffuser for use in a centrifugal compressor research facility was designed and implemented. Utilizing an AM process to manufacture the diffuser reduces the long lead time that is associated with conventionally manufactured diffusers, and it increases the instrumentation capabilities within the flow path. Several AM techniques and a variety of plastic and metal materials were evaluated for this application. A high-temperature, stereolithography (SL) resin was chosen because of the tight dimensional tolerances maintained by the SL process. Utilizing a high-temperature plastic also results in manufacturing costs that are significantly less than using a metal material. Samples of the chosen material were subjected to mechanical testing to investigate the effects of build direction and to verify its properties in the high-temperature compressor environment. To fit within the manufacturing space of an SL machine, the AM diffuser consists of seven radially symmetric sections that are assembled to form a complete flow path. Considerations for modifying the research facility to allow for this unique installation are presented. Precision measurements of the AM components were obtained to compare printed and modeled geometry, and they demonstrate close alignment of flow path dimensions.