CFD Analysis of a 15 Stage Axial Compressor: Part I — Methods

Abstract

The flow field of a 15 stage axial compressor is analyzed using a 3-D Navier-Stokes CFD tool. The compressor under investigation is a prototype first compressor version before optimization of the Siemens V84.3A family. A methodology is described for steady state and transient flow simulations of the entire 15 stages compressor in one computation (not piece by piece). The simulation includes tip gaps, mass bleeds, hub leakage flows, and ranges from single passage to full 360 degrees analysis. The work is divided into two companion papers. This first part, “CFD Analysis of a 15 Stage Axial Compressor Part I: Methods” describes the overall methodology used, based on a middle portion of the compressor R5S9 (Rotor 5 to Stator 9). Various effects are analyzed: mesh style and refinement, boundary conditions, steady or transient, tip clearance, and numerical issues (turbulence model choice, advection model choice, parallel processing performance). A high sensitivity of the predictions to the tip clearance height was found. Excellent design point predictions are obtained with steady-state frame change interface models (Stage average interface), as well as with transient simulations (transient rotor-stator interface).