Numerical Investigation of the Secondary Instability in Baffled-Channel Flows
*Streamlines and Pressure Contours in baffled channel flow

*Number of grid points: 96 * 96

*Re (Reynolds number) = 130

Sponsored by Korea Research Foundation
Principal Investigator: Kyung-Soo Yang
Assistants: Jong-Yeon Hwang ,In-Sang Hwang
Transitional flow in an obstructed channel is investigated using  Direct Numerical Simulation. Two-dimensional thin obstacles("baffles")  are mounted symmetrically in the vertical direction and periodically in  the streamwise direction. Flow separation occurs at the tip of the sharp  obstacles. Depending on the Reynolds number, the flow undergoes  Hopf bifurcation as the primary instability leading to an unsteady
periodic solution. Then, at a high Reynolds number,  three-dimensional secondary instability takes place, and the flow  becomes chaotic. All these results are consistent with the  experimental findings currently available.
Related paper:Kyung-Soo Yang, Numerical investigation of instability and transition in an obstructed channel flow , 2000, AIAA Journal, Vol. 38, No. 7, pp. 1173-1178.