Time resolved simulation of particle rebound for erosion calculation in jet aero engines

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In the present research proposal, the mechanical damage to material by the impact of solid particles transported in the surrounding fluid, also known as erosion, is to be investigated. The aim is to improve the performance degradation prediction of turbo aero engines by a combined numerical and experimental approach.The erosive particles enter the gas path of the engines as part of the air flow and damage the components, especially the blades. The eroded geometry leads to deviations in the aerodynamics and thus to a deterioration of the performance of the component. The shape change of the components is determined by the trajectory of the particles. Due to the complex geometries of the gas path of aircraft engines, the exact trajectory of these erosive particles is difficult to predict. The trajectories are determined by aerodynamic forces but also by the rebounding behavior of the particles on the walls of the gas path or the blades. Existing rebound models are not accurate enough or have not been investigated at the particle velocities relevant for turbo aero engines. In addition, the numerical methods currently used in industry only compute the time-averaged flow fields and neglect unsteady, turbulent motion and its effect on particle behavior.Therefore, a combined numerical and experimental research project should clarify this question. We combine our expertise in such way that numerical and experimental investigations validate and control each other. With its existing erosion test rig, the Institute of Aircraft Propulsion Systems will investigate the rebound behavior under typical conditions of a high-pressure compressor of a modern turbojet engine. The results are handed over to the Institute for Aerodynamics and Gas Dynamics. The Institute for Aerodynamics and Gas Dynamics, with its existing numerical flow mechanics software, simulates the flow as well as the particle trajectories. Through intensive exchange of the two institutes, the rebound conditions for flat plates, plates with a leading edge radius and a compressor cascade will be studied numerically and experimentally. The aim is therefore to develop a combined experimental-numerical analysis tool during the project that is capable of predicting rebound and erosion behavior in industrially relevant geometries with up-to date not achieved accuracy.