Deposition of sand particles on a solid substrate in a high-temperature subsonic flow

TL;DR

This study uses two-way coupled Euler-Lagrange simulations to analyze how sand particles deposit on turbine blades in high-temperature, subsonic flows, revealing factors influencing deposition and rebound behavior.

Contribution

It introduces a detailed simulation approach to study sand particle deposition on turbine blades at high temperatures, considering different particle types and flow conditions.

Findings

Deposition rates vary with particle type and flow conditions.

Rebound velocity depends on Stokes number and particle properties.

Simulation results inform turbine blade damage mechanisms.

Abstract

Ingestion of sand particles into gas turbine engines has been observed to cause damage to engine components and in some cases leads to catastrophic failure. One such mechanism responsible for engine failure occurs through the deposition of molten particles on the turbine blades in the hot-section of the engine. The deposited material reacts chemically and penetrates the thermal barrier coating (TBC) on the turbines blades eventually damaging them. In this work, we investigate the deposition of sand particles on a solid substrate using two-way coupled Euler-Lagrange simulations. In these simulations, hot gas at 1700 K is issued from a circular inlet at Mach 0.3. Simultaneously, spherical mono-dispersed sand particles, modeled after the Calcia-Magnesia-Alumino-Silicates(CMAS), are injected at a constant mass flow rate of 1 gram per minute. The deposition of these particles on a solid substrate, placed 20 cm away from the inlet along the axial direction, is investigated. Simulations are carried out for three different synthetic sand particles CMAS, AFRL 02 and AFRL 03. The effect of Stokes number on particle properties such as number of particle depositions, rebound velocity and coefficient of restitution are investigated.