Investigation of aerodynamic effects in stator components of multistage centrifugal compressors

Abstract

Multistage radial compressors are major components in many industrial applications. Today, compressor downsizing for CAPEX (capital expenditure) reduction is of utmost importance. To attain the most compact design, the pressure ratio must increase, and there must be no reduction in performance levels achieved in more conventional machines. To investigate the complex flow in the stator parts of multistage centrifugal compressors and to increase the confidence level of numerical methods, a new test rig was developed. This test rig allows for the separation of stationary flow effects from time-variant effects, leading to in-depth insight into physical flow features. The aim is to investigate the flow in different stator designs for varying flow coefficients. Additive manufacturing techniques were applied for the production of parts to be tested with the aim to achieve low costs simultaneously with short production time. In this paper, the test rig design is described in detail. The configuration of the measuring planes is depicted, and the multiple measuring techniques are described. The measurement accuracy and uncertainties are discussed. Subsequently, measurement data such as pressure as well as velocity profile plots for steady-state conditions are presented. Finally, the performance of stator parts regarding pressure loss and pressure recovery coefficients is discussed.