Quantitative Computational Fluid Dynamics Analyses of Particle Deposition on a Subsonic Axial Compressor Blade

Abstract

In literature, there are some studies related to the fouling phenomena in transonic compressors, but, in industrial applications (heavyduty compressor, pumping stations, etc.) the subsonic compressors are widespread. It is of great interest to the manufacturer to discover the fouling phenomenon related to this type of compressor. This paper presents threedimensional numerical simulations of the microparticle ingestion on a subsonic axial compressor rotor carried out by means of a commercial computational fluid dynamic code. Particle trajectory simulations use a stochastic Lagrangian tracking method that solves the equations of motion separate from the continuous phase. The number of particles, sizes, and concentrations are specified in order to perform a quantitative analysis of the particle impact on the blade surface. In this paper, the particle impact pattern and the kinematic characteristics (velocity and angle) of the impact are shown. Both of the blade zones affected by particle impact and the blade zones affected by particle deposition are analyzed. The particle deposition is established by using the quantity called sticking probability (SP). The SP links the kinematic characteristics of particle impact on the blade with fouling phenomenon. The results show that microparticles tend to follow the flow by impacting at full span with a higher impact concentration on the leading edge (LE). The suction side (SS) is affected only close to the LE and, at the hub, close to the trailing edge (TE). Particular fluiddynamic phenomena such as separation, stagnation, and tip leakage vortex strongly influence the impact location of the particles. The kinematic analysis showed a high tendency of particle adhesion on the SS, especially for smaller particles for which the fluid dynamic phenomena play a key role regarding particle impact velocity and angle.