| Autor: |
Volodymyr G. Basovsky, Olha V. Khomenko, Iryna M. Gorban |
| Rok vydání: |
2018 |
| Předmět: |
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| Zdroj: |
Understanding Complex Systems ISBN: 9783319967547 |
| Popis: |
The hybrid numerical technique coupled with the vortex method for simulation of viscous incompressible flow and the Ffowcs William-Hawkings acoustic analogy is applied to the investigation of hydrodynamic and acoustic fields generated by a two-dimensional open cylindrical cavity. The problem is considered for a thin laminar boundary layer before the cavity and with the Reynolds number of Re = 2 ⋅ 104, based on the cavity chord. The obtained results indicate that the cavity flow oscillates in the shear-layer mode and radiates a dipole in the far acoustic field so that the sound intensity in the backward direction is higher than in the forward direction. The effectiveness of controlling of the flow oscillations by applying steady suction through the rear cavity wall is studied. The results show that the suction allows us to localize the vortical flow inside the cavity when saving the mode of self-sustained oscillations in the shear layer. The vortices generated in the shear layer do not hit the trailing edge now but are absorbed by the suction causing the rise of pressure fluctuations in the vicinity of suction point. As a result, the obtained levels of radiated sound are much higher than in the uncontrolled cavity flow. The obtained positive effect of the suction on the cavity flow is that it suppresses the pressure fluctuations on the wall portion behind the cavity that leads to stabilization of the attached boundary layer. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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