Numerical Studies of Instability and Transition in a Baffled Channel Flow

초록

Instability and transition in a baffled channel are investigated using numerical simulation. Flow geometry under consideration is a plane channel with two-dimensional thin obstacles (``baffles") mounted symmetrically in the vertical direction and periodically in the streamwise direction. The flow undergoes a Hopf bifurcation as the Reynolds number increases, leading to an unsteady periodic solution. At higher Reynolds numbers, the unsteady flow exhibits a symmetry-breaking bifurcation. A secondary instability is also observed at higher Reynolds numbers, which is believed to be responsible for subsequent chaotic breakdown of the flow. Numerical results obtained are consistent with experimental findings currently available.