Philip Jimmy, Svizher Alexander, Cohen Jacob
Faculty of Aerospace Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel.
Phys Rev Lett. 2007 Apr 13;98(15):154502. doi: 10.1103/PhysRevLett.98.154502.
The scaling law for the threshold amplitude of perturbations to initiate a transition in subcritical plane Poiseuille flow as a function of the Reynolds number is demonstrated experimentally. The disturbances are introduced through an almost streamwise independent slot drilled at the bottom wall of a horizontal air-channel flow. Following the two stages of transition, linear transient growth and nonlinear secondary instability, it is found that the normalized critical injection rate (v0) scales with the Reynolds number (R) as v0 approximately R-3/2. This scaling law agrees with the theoretical predictions of Chapman [J. Fluid Mech. 451, 34 (2002).].
实验证明了在亚临界平面泊肃叶流中引发转变的扰动阈值幅度随雷诺数变化的标度律。扰动通过在水平空气通道流底壁钻出的几乎沿流向独立的狭缝引入。经过线性瞬态增长和非线性二次失稳这两个转变阶段后，发现归一化临界注入率（v0）与雷诺数（R）的标度关系为v0约为R^(-3/2)。该标度律与查普曼的理论预测[《流体力学杂志》451, 34 (2002)]相符。
