Nonlinear evolution of singular disturbances to a tanh(3) y mixing layer

作者：Saujani S^*; Drozd J; Mallier R

来源：ANZIAM Journal, 2002, 43: 409-427.

We consider the nonlinear evolution of a disturbance to a mixing layer, with the base profile given by u(0)(y) = tanh(3) y rather than the more usual tanh y, so that the first two derivatives of u(0) vanish at y = 0. This flow admits three neutral modes, each of which is singular at the critical layer. Using a non-equilibrium nonlinear critical layer analysis, equations governing the evolution of the disturbance are derived and discussed. We find that the disturbance cannot exist on a linear basis, but that nonlinear effects inside the critical layer do permit the disturbance to exist. We also present results of a direct numerical simulation of this flow and briefly discuss the connection between the theory and the simulation.

• 出版日期2002-1