%0 Journal Article %A N. K. Singh and S. Sarkar %D 2011 %J International Journal of Mechanical and Mechatronics Engineering %B World Academy of Science, Engineering and Technology %I Open Science Index 57, 2011 %T DNS of a Laminar Separation Bubble %U https://publications.waset.org/pdf/11403 %V 57 %X Direct numerical simulation (DNS) is used to study the evolution of a boundary layer that was laminar initially followed by separation and then reattachment owing to generation of turbulence. This creates a closed region of recirculation, known as the laminar-separation bubble. The present simulation emulates the flow environment encountered in a modern LP turbine blade, where a laminar separation bubble may occur on the suction surface. The unsteady, incompressible three-dimensional (3-D) Navier-Stokes (NS) equations have been solved over a flat plate in the Cartesian coordinates. The adverse pressure gradient, which causes the flow to separate, is created by a boundary condition. The separated shear layer undergoes transition through appearance of ╬ø vortices, stretching of these create longitudinal streaks. Breakdown of the streaks into small and irregular structures makes the flow turbulent downstream. %P 1757 - 1761