The effects of particle stokes number on particle dynamics in a linear cascade

Gas turbine engines are highly susceptible to damage caused by particles as they enter the engine and impact the compressor blades. Analyzing particle trajectories within a compressor is important to prevent damage to the components. A simpler solution to extracting data from experimental turbomachinery is to create a linear cascade of airfoils to analyze the flow physics. This study uses different turbulence modeling techniques to predict the particle trajectories in a linear cascade. RANS turbulence models and LES turbulence models are used to determine a quantitative analysis of particle trajectories, impact locations and erosion. The Stokes Number (St) is used to characterize the importance of particle size. Smaller St particles act as tracers and follow the flow streamlines while the large St particles are more ballistic in nature. St≈1 are light enough to be affected by the flow, but also large enough that it does not act as a tracer. Particles with different St are tested to observe the dependence of particle diameter on the impact locations, the erosion occurring, as well as the energy lost on impact. Particles are tested with the coefficient of restitution set to 0 and 1 to mimic particle sticking to and rebound off compressor blades, respectively.