Application of a Synthetic Jet to Control Boundary Layer Separation under Ultra-High-Lift Turbine Pressure Distribution |
| |
Authors: | Davide Lengani Daniele Simoni Marina Ubaldi Pietro Zunino Francesco Bertini |
| |
Institution: | 1.DIMSET,Università di Genova,Genova,Italy;2.Avio R.?D.,Rivalta (TO),Italy |
| |
Abstract: | The transition and separation processes of the boundary layer developing on a flat plate under a prescribed adverse pressure
gradient typical of Ultra-High-Lift low-pressure turbine profiles have been investigated, with and without the application
of a synthetic jet (zero net mass flow rate jet). A mechanical piston has been adopted to produce an intermittent flow with
zero net mass flow rate. The capability of the device to suppress or reduce the large laminar separation bubble occurring
under steady inflow condition at low Reynolds numbers has been experimentally investigated by means of hot-wire measurements.
Wall static pressure measurements complement the hot-wire time-resolved velocity results. The paper reports the investigations
performed for both steady and controlled conditions. The active device is able to control the laminar separation bubble induced
at low Reynolds number conditions by the strong adverse pressure gradient. An overall view of the time-dependent evolution
of the controlled boundary layer is provided by the phase-locked ensemble averaging technique, triggered at the synthetic
jet frequency. The separated flow transition process, which is detected for the uncontrolled condition, is modified by the
synthetic jet in different ways during the blowing and suction phases. Overall, the phase-locked velocity distributions show
a reduced separated flow region for the whole jet cycle as compared to the uncontrolled condition. The phase-locked distributions
of the random unsteadiness allow the identification of vortical structures growing along the shear layer mainly during the
blowing phase. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|