Alternate Passage Divergence of Aeroengine Fan Blades

该项目将研究气动载荷对结构变形的影响，旨在提高对旋转机械中强流固耦合的理解。在叶片系统中，如燃气和风力涡轮机，时变气动载荷不仅会引起振动问题，还会导致叶片的准静态或瞬态变形，由于制造差异或使用中磨损，叶片的变形会因叶片而异。由此产生的不均匀性，也称为交替通道散度，对效率有不利影响。由于非线性气动和结构效应以及与制造公差和使用磨损相关的随机不确定性，这种行为的建模是困难的。目前尚无可靠的预测方法或应对措施。考虑到初步简化的几何形状，本项目将开发一种能够准确预测暂态交替通道散度的数值方法。在第一步中，将非线性非定常reynolds -average Navier-Stokes解算器与非线性结构模型耦合，并在简化的几何模型上验证这一点，以评估包含非线性效应对于准确预测结构变形的重要性。在第二步中，它将使用不确定性分析方法，并确定所产生的结构变形对输入几何形状的几何变化的敏感性。该项目预计将提供一个强大的设计方法，表现出强烈的流固耦合。

The project will investigate the influence of aerodynamic loads on the deformation of structures with the aim to improve the understanding of strong fluid-structure coupling in rotating machinery. In bladed systems, such as gas and wind turbines, time-varying aerodynamic loads cannot only cause vibration issues but also lead to a quasi-static or transient deformation of the blades, which varies from blade to blade due to manufacturing difference or in-service wear. This resulting non-uniformity, also known as alternate passage divergence, has adverse effects on efficiency. Modelling this behaviour is difficult due to non-linear aerodynamic and structural effects and the random uncertainty associated with manufacturing tolerances and in service wear. Currently, no reliable prediction methods or counter measures exists. Considering initially simplified geometries, this project will develop a numerical method which can accurately predict transient alternate passage divergence. In the first step, it will couple a non-linear unsteady Reynolds-averaged Navier-Stokes solver with a non-linear structural model and validate this on simplified geometries to assess the importance of including non-linear effects for the accurate prediction of structural deformations. In the second step, it will use uncertainty analysis methods and identify the sensitivity of resulting structural deformations to geometric changes in the input geometries. The project is expected to deliver a robust methodology for designs which exhibit strong fluid-structure coupling.