Numerical Investigation of Sand Erosion Phenomena in Transonic Fan of Jet Engine

砂蚀是一种固体颗粒撞击壁面造成壁面严重机械损伤的现象。该现象是一种典型的气固两相湍流流动，可以看作是流场、颗粒运动轨迹和壁面变形相互作用的多物理问题。另一方面，在颗粒环境中操作的航空发动机由于沙侵蚀而遭受性能和寿命劣化。因此，在开发中必须证明，当发动机吸入一定量的沙子时，发动机可以无故障地运行。在本研究中，我们应用我们的三维沙侵蚀预测程序的跨音速风扇，并阐明了物理机制。在2008年，粒子运动通过激波，这通常出现在跨音速风扇叶片通道，进行了建模和验证。在2009年，我们新开发了一个三维风扇转子/定子干扰场的泥沙磨损预测代码。采用NASA Rotor 37作为代码验证的目标。2011年，该代码被应用于风机叶片的不同工况。通过对数值计算结果的分析，阐明了流场的变化、叶片表面的砂蚀现象、受砂蚀叶片的几何形状以及性能的恶化。

Sand erosion is a phenomenon whereby solid particles impinging on a wall cause serious mechanical damage to the wall surface. This phenomenon is a typical gas-solid two-phase turbulent flow and can be considered as a multi-physics problem in which the flow field, particle trajectory, and wall deformation interact. On the other hand, aircraft engines operating in a particulate environment are subjected to the performance and lifetime deterioration due to sand erosion. Therefore, in the development it must be proved that the engine can operate without any trouble when a certain amount of sand is sucked in the engine. In the present study, we apply our three dimensional sand erosion prediction code to a transonic fan, and clarify the physical mechanism. In 2008, a particle motion through a shock wave, which generally appears in a transonic fan blade passage, was modeled and verified. In 2009, we newly developed a sand erosion prediction code for a three-dimensional rotor/stator interaction field of a fan. NASA Rotor 37 was adopted as the target of the code verification. In 2011, the code was applied to different operating conditions of fan blade. Investigating the numerical results, the flow change, the sand erosion phenomena on the blade, the eroded blade geometry and the performance deterioration were clarified.