Mathematical Sciences: Solitons and the Onset of Chaotic Pulsation in Boundary Layers

数学科学：孤子和边界层中混沌脉动的发生

• 批准号: 9404315
• 负责人: Julian Cole
• 金额: $ 7万
• 依托单位: Rensselaer Polytechnic Institute
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-07-01 至 1996-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9404315&HistoricalAwards=false
• 关键词: Mathematical; Sciences; Solitons; Onset; Chaotic

9404315 Cole Aspects of essentially nonlinear stability in the laminar boundary layer will be considered in the framework of the asymptotic triple deck theory. Disturbances in the free stream such as vorticity or sound result in wave packets which undergo explosive growth. The nonlinear disturbances are described by a forced Benjamin-Ono equation. Chaotic pulsations are expected to result on the way to transition. The results here have their primary application to the prediction of laminar-turbulent transition in boundary layer flows, such as those on aircraft or in jet engines. The understanding and control of turbulence will make more efficient designs possible. Similar disturbances have been observed in the atmosphere where large nonlinear wave systems appear. The theoretical work here can lead to a better understanding of the interaction of topography and storms.

小科尔9404315 层流边界层中本质上非线性稳定性的各个方面将在渐近三层理论的框架内加以考虑。 自由流中的扰动，如涡量或声音，导致波包爆炸性增长。 非线性扰动由强迫Benjamin-Ono方程描述。 混沌脉动预计会在过渡的过程中产生。 本文的结果主要应用于预测边界层流中的层流-湍流转捩，如飞机或喷气发动机中的边界层流。 对湍流的理解和控制将使更有效的设计成为可能。 在大气中也观察到了类似的扰动，那里出现了大的非线性波系。 这里的理论工作可以更好地理解地形和风暴的相互作用。