Numerical Study on the Flow Characteristic in Periodical Variable Cross-section Channel

The flow characterizations through periodical variable cross-section passage are performed by numerical simulations in the one wavelength passage with periodic inlet and outlet boundary conditions. The flow patterns through the transient method in the passage show the steady characteristic at low Reynolds number, and the unsteady characteristics include either occurrence or development of self-sustained oscillations as the increasing of Reynolds number. As a consequence of these flow characteristics, the fluid mixing between the core flow and vortexes in trough or crest in channel can be improved to increase the heat transfer.