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ISSN Online: 2377-424X

ISBN Print: 978-1-56700-421-2

International Heat Transfer Conference 15
August, 10-15, 2014, Kyoto, Japan

Effects of System Rotation on Transitional Boundary Layer

Get access (open in a dialog) DOI: 10.1615/IHTC15.ttr.008909
pages 9201-9215

Resumo

The effects of anticyclonic system rotation on the spatially developing transitional boundary layer are studied by using the spectral methods of DNSs with fringe region. By using the forcing term limited in the fringe region at the edge of the computational domain, the outlet flow condition is forced to be identical with inflow condition, which makes the spectral method applicable to the spatially developing boundary layer. Visualization of the numerical results shows that generation of the low-speed streaks and roll vortices are found to be followed by oscillation and breakdown of the low-speed streaks and generation of arch vortices. Imposing anticyclonic system rotation makes the flow unstable and tends to make transition i.e., both low-speed-streaks generation and their breakdown, occur at shorter distance from the inlet condition. In all cases of system rotation, however, generation of low-speed streaks is related to roll vortices and enhancement of ejection motion, i.e., outward motion of low-speed fluids from the wall, while their breakdown is more related to arch vortices and sweep motion, i.e., inrush motion of high-speed fluids toward the wall than ejection motion.