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

在目前的研究方案中，要研究的是固体颗粒在周围流体中传输的冲击对材料的机械损伤，也称为侵蚀。目的是通过数值计算和实验相结合的方法来提高涡轮增压航空发动机性能退化预测的精度。被侵蚀的几何形状导致空气动力学的偏差，从而导致部件性能的恶化。部件的形状变化由粒子的轨迹决定。由于飞机发动机气路的复杂几何形状，这些腐蚀性颗粒的确切轨迹很难预测。轨迹由空气动力决定，也由气路或叶片壁上颗粒的反弹行为决定。现有的回弹模型不够准确，或者没有在与涡轮航空发动机相关的粒子速度下进行研究。此外，目前工业上使用的数值方法只计算时间平均的流场，而忽略了非定常、湍流运动及其对颗粒行为的影响，因此，一个数值和实验相结合的研究项目应该澄清这个问题。我们将我们的专业知识结合在一起，使数值研究和实验研究相互验证和控制。利用现有的冲蚀试验台，飞机推进系统研究所将研究现代涡喷发动机高压压气机在典型条件下的反弹行为。结果被移交给空气动力学和气体动力学研究所。空气动力学和气体动力学研究所利用其现有的数值流动力学软件来模拟流动和颗粒轨迹。通过两所的深入交流，将对平板、前缘半径平板和压气机叶栅的回弹条件进行数值和实验研究。因此，目的是在项目期间开发一种实验-数值分析相结合的工具，该工具能够预测与工业相关的几何图形中的反弹和侵蚀行为，但迄今尚未达到精度。

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.