Control of a swept-wing boundary layer perturbed by free-stre am turbulence

壁面吸力已被广泛用于减少层流边界层扰动的增长，如Tollmien-Schlichting波、横流涡以及最近的k黎巴嫩夫模式，即由自由流涡旋扰动产生的非定常流向延长低频扰动。壁面吸力延迟了向湍流的过渡，其主要好处是减少了粘性阻力、噪音和燃油消耗。所提出的工作的中心目标是利用壁面吸力来减弱后掠翼层流边界层中由于自由流湍流而产生的克莱巴诺夫模态的强度。尽管这些流动结构在许多工业和技术应用（如飞机机翼和涡轮叶片的设计）中具有巨大的重要性，但它们从未在大型气动体上进行过研究。壁面吸力对这些技术相关流动的影响尚未进行研究。工程缺乏的一个原因是预测和控制这种流动极其困难。这个问题将通过数学和数值技术的结合来解决。所提出的方法将提供一个快速和数字上强大的工具包，符合流体力学社区长期以来的努力，以有效的方式控制过渡前流动。

Wall suction has been used extensively to reduce the growth of laminar boundary layer disturbances, such as Tollmien-Schlichting waves, cross-flow vortices and, more recently, Klebanoff modes, namely unsteady streamwise-elongated low-frequency disturbances generated by free-stream vortical perturbations. Wall suction has resulted in a delay of transition to turbulence with major benefits, such as reduction of viscous drag, noise, and fuel consumption.The central aim of the proposed work is to apply wall suction to attenuate the intensity of Klebanoff modes arising in swept-wing laminar boundary layers due to free-stream turbulence. These flow structures have never been studied over large scale aerodynamic bodies, despite their vast importance in numerous industrial and technological applications, such as the design of aircraft wings and turbine blades. The effects of wall suction have not been investigated for these technologically relevant flows. A reason for the dearth of works is the extreme difficulty in predicting and controlling such flows.The problem will be tackled by a combination of mathematical and numerical techniques. The proposed approach will offer a fast and numerically robust toolkit in line with the long-standing effort of the fluid mechanics community to control pre-transitional flows in an efficient manner.