Modeling Deposit Erosion in Internal Turbine Cooling Geometries

Abstract

Experiments were performed to study the erosion of deposit structures due to large particle impacts (>5 μm). Cone-shaped dust deposits were created in an oversized (6.35 mm diameter) impingement cooling jet at 811 K with 0–5 μm Arizona road dust (ARD). Subsequently, the deposit cones were eroded with larger particle distributions (5–10, 10–20, 20–40, and 40–80 μm ARD) at various velocities and temperatures. It was found that erosion rate increased with increasing particle size and flow velocity and with decreasing temperature. The dependency on size and velocity occurs through the particle's kinetic energy at impact, while the dependency on temperature is related to the adhesive forces in the deposit structure. Using the experimental data, an empirical erosion model was developed to be added to the Ohio State University (OSU) deposition model. A computational flow simulation combined with mesh morphing is shown to capture key features of the erosion physics.