PSE在边界层中预测转捩位置的应用

层流到湍流的转捩是自然界和各项工程实践中广泛存在的现象，层流和湍流的性质大不相同．因此，预测转捩位置是流体力学中的重要理论和实际问题．针对不可压缩边界层，入口加入展向等幅值型和展向波包型两类扰动，展向等幅值型扰动是由一个二维波(2-D)和两个三维波(3-D)组成，使用抛物化稳定性方程(PSE)的方法来研究扰动的演化和预测转捩位置，并且与数值模拟的结果相比较．结果表明，PSE可以研究扰动的演化和预测转捩位置，同时其计算比数值模拟快得多．

Applications of PSE to Predict the Transition Position in Boundary Layers

The phenomenon of laminar-turbulent transition exists universally in nature and various engineering practices.The prediction of transition position was one of crucial theories and practical problems in fluid mechanics due to different natures of laminar flow and turbulent flow.Two types of disturbances imposed at the entrance were identical amplitude and wavepacket disturbances along the spanwise in incompressible boundary layers.The disturbances of identical amplitude consist of a two-dimensional(2-D) wave and two three-dimensional(3-D) waves.The parabolized stability equation(PSE) was used to research the evolution of disturbances and predict the transition position,and the results were compared with those obtained by numerical simulation.It’s revealed that the PSE method could investigate the evolution of disturbances and predict the transition position.At the same time,the speed of calculation was much faster than numerical simulation.