Particle Transport Analysis of Sand Ingestion in Gas Turbine Engines

Significant interest exists in the military and commercial aerospace industry to better predict and improve the durability of gas turbine jet engines that are operating in hostile desert environments, specifically, jet engines that see significant inlet sand or ash ingestion. This paper describes the development of a mixed CFD-empirical software tool that allows a detailed analysis of the kinematic and impact behavior of sand and other particulates in the near-field of turbomachinery blades and impellers. The tool employs a commercially available CFD solver to calculate the machine’s transient flow field and then uses the output to determine a set of nondimensional coefficients in a set of empirical functions to predict the statistical probability of particles impacting on rotating or stationary surfaces. Based on this tool’s output information, improved inlet air filtering techniques, optimized engine maintenance practices, and component designs can be realized. To determine the empirical coefficient and to validate the method, PIV testing was performed on an airfoil in a wind tunnel; then particle injection into a simple rotating impeller was tested on SwRI’s high-speed compressor test rig. Results from these tests allowed optimizing of the model to reflect rotating machinery particle impact behavior more accurately.