Numerical study of ribbon-induced transition in Blasius flow
Numerical study of ribbon-induced transition in Blasius flow
复制标题
Blasius 流中带状诱导转变的数值研究
作者：
P. Spalart;Kyung
本文用数值解Navier-Stokes方程的方法研究了Blasius边界层转捩的早期三维阶段。引入了有限振幅二维波动和低振幅三维随机扰动。观察到三维成分的快速放大并导致过渡。对于二维波的中间振幅，击穿是亚谐波类型的，并且主展向波数随着振幅而增加。对于高振幅的能量的基本模式是可比的能量的次谐波模式，但从来没有占主导地位，它的崩溃是混合型。可视化，能源的历史，和光谱。各种物理和数值参数的结果的敏感性进行了研究。与实验和理论结果的协议进行了讨论。
The early three-dimensional stages of transition in the Blasius boundary layer are studied by numerical solution of the Navier-Stokes equations. A finite-amplitude two-dimensional wave and low-amplitude three-dimensional random disturbances are introduced. Rapid amplification of the three-dimensional components is observed and leads to transition. For intermediate amplitudes of the two-dimensional wave the breakdown is of subharmonic type, and the dominant spanwise wavenumber increases with the amplitude. For high amplitudes the energy of the fundamental mode is comparable to the energy of the subharmonic mode, but never dominates it; the breakdown is of mixed type. Visualizations, energy histories, and spectra are presented. The sensitivity of the results to various physical and numerical parameters is studied. The agreement with experimental and theoretical results is discussed.