Unsteady wake-blade interaction is an inevitable consequence of the relative motion between rotors and stators in turbomachines. The flow in a low-pressure stage has a relatively low Reynolds number, of order 10 5 , based on chord length, and a substantial proportion of the boundary layer on the blade surface is thus laminar or transitional. While the flow in a turbine accelerates, globally, th...

The primary objective of this study is to evaluate the accuracy of using computational fluid dynamics (CFD) turbulence models to predict entropy generation rates in bypass transitional boundary layers flows under zero and adverse pressure gradients. Entropy generation rates in such flows are evaluated employing the commercial CFD software, ANSYS FLUENT. Various turbulence and transitional model...

To eliminate the problem with artificial boundary conditions and facilitate the use of Fourier methods, the fringe region (or filter, damping layer, absorbing layer, sponge layer) technique has been used in direct simulations of transitional and turbulent boundary layers. Despite the fact that good computational results have been obtained with this technique, it is not fully understood. The ana...

Control of a transitional laminar separation bubble using steady and unsteady 2D and 3D Tollmien-Schlichting (TS) like boundary-layer disturbances is investigated by means of direct numerical simulations. The specific influence of different disturbance modes which allow an effective reduction of the reverse-flow region is illustrated. It is shown that unsteady 2D or 3D control is more efficient...