Desktop Use of Computational Fluid Dynamics to Design and Troubleshoot Compressors and Turboexpanders

For several decades, turboexpander designers have relied on experience and traditional design tools to create their products. Recent advances in CFD (computational fluid dynamics) software and desktop computing power have made it possible for some manufacturers to investigate unique fluid flow fields in routine design applications. In this paper, four case studies of CFD in high performance expanders and compressors are discussed. The first case study shows CFD used as a screening tool for a radial inflow turbine stage. The second demonstrates a challenging compressor design, where CFD was integrated into the design process. The third case study details the uncommon application of CFD to a fluid film thrust bearing, showing comparisons to traditional bulk flow calculations. The fourth case study highlights the use of CFD in troubleshooting a centrifugal compressor stage. The CFD solution was subsequently verified by factory testing, and the equipment is successfully operating in the field. 71 DESKTOP USE OF COMPUTATIONAL FLUID DYNAMICS TO DESIGN AND TROUBLESHOOT COMPRESSORS AND TURBOEXPANDERS