Predictive Modelling of Engine Inlet Distortion in Crosswind Conditions

侧风条件下发动机进气道变形的预测建模

• 批准号: 513713-2017
• 负责人: Hickey, JeanPierre
• 金额: $ 1.82万
• 依托单位: University of Waterloo
• 依托单位国家: 加拿大
• 项目类别: Engage Grants Program
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=640022
• 关键词: Predictive; Modelling; Engine; Inlet; Distortion

The intake of aircraft engines is constructed to provide a steady and uniform flow over a wide range ofoperating conditions. Nacelles are designed to optimize cruise efficiency while meeting the stringentoperational requirements at off-design conditions. One of the most critical operating points occurs on theground with severe crosswinds when the aircraft is at rest. In this setup, the crosswind causes a stagnation pointto occur on the outer nacelle, the flow then accelerates and transitions around the lip before entering the engineat a near-sonic speed. The negative pressure gradient at the engine inlet results in flow separation, whichdistorts the incoming flow stream; at sufficiently large distortion levels, stall or aerodynamic instabilities of thefan blades may arise. The accurate prediction of the engine inflow distortion is extremely difficult as it involveslaminar-to-turbulent transition, complex geometry and pressure gradients and flow separation. This projectseeks to improve on existing transitional models to accurately determine the onset of transition on a complexthree-dimensional nacelle, and thus improve the prediction accuracy of inflow distortion at these criticaloff-design conditions.

航空发动机进气道的结构是为了在各种工作条件下提供稳定均匀的气流。短舱的设计是为了优化巡航效率，同时满足非设计条件下的弦线操作要求。最关键的工作点之一发生在地面上，当飞机静止时，有严重的侧风。在这种设置中，反风导致在外部发动机舱上出现驻点，然后气流加速并在接近音速的速度进入发动机之前绕唇缘过渡。发动机进口处的负压梯度导致气流分离，使进入的气流发生畸变;在足够大的畸变水平下，可能引起风扇叶片的失速或气动不稳定性。发动机来流畸变的准确预测是极其困难的，因为它涉及层流到湍流的转变、复杂的几何形状和压力梯度以及流动分离。该项目旨在改进现有的转捩模型，以准确地确定复杂三维短舱的转捩开始，从而提高这些临界非设计条件下的入流畸变的预测精度。