Numerical Simulation of Particulates in Multistage Axial Compressors

Abstract

Aircraft engines ingest airborne particulate matter, such as sand, dirt, and volcanic ash, into their core. The ingested particulate is transported by the secondary flow circuits via compressor bleeds to the high pressure turbine and may deposit resulting in turbine fouling and loss of cooling effectiveness. Prior publications focused on particulate deposition and sand erosion patterns in a single stage of a compressor or turbine. This work addresses the migration of ingested particulate through the high pressure compressor (HPC) and bleed systems. This paper describes a 3D CFD methodology for tracking particles along a multistage axial compressor and presents particulate ingestion analysis for a high pressure compressor section. The commercial CFD multiphase solver ANSYS CFX® has been used for flow and particulate simulations. Particle diameters of 20, 40, and 60 μm are analyzed. Particle trajectories and radial particulate profiles are compared for these particle diameters. The analysis demonstrates how the compressor centrifuges the particles radially toward the compressor case as they travel through the compressor; the larger diameter particles being more significantly affected. Nonspherical particles experience more drag as compared to spherical particles, and hence a qualitative comparison between spherical and nonspherical particles is shown.

Effect of open crack on axial compressor performance

“…In some harsh operating conditions, the compressor bleeds air with particles that strike the blade and attach to its surface. 8 If the water content of the air is too large, it may also cause blade corrosion, which will lead to the increase of surface roughness and the tip clearance to affect aerodynamic performance. Previous researches have investigated the effects of blade surface roughness by numerical simulations and experiments, and found that increased roughness leads to more flow losses, and increased tip clearance due to corrosion also reduces compressor performance.…”

Quantitative Computational Fluid Dynamics Analyses of Particle Deposition in a Heavy-Duty Subsonic Axial Compressor

“…A particular computational strategy is adopted to take into account the presence of two subsequent annular cascades. Recently, Saxena et al [11] have performed a numerical study of a high-pressure axial compressor ingesting particulate matter, in order to predict particle behavior both along the stages and the compressor bleed system. The effect of particle shape is also studied by simulating nonspherical particles.…”