| Full text | |
| Author(s): |
Ricciardi, Tulio R.
;
Wolf, William R.
Total Authors: 2
|
| Document type: | Journal article |
| Source: | PHYSICAL REVIEW FLUIDS; v. 7, n. 8, p. 21-pg., 2022-08-03. |
| Abstract | |
Large eddy simulations are performed to study tonal noise generation by a NACA0012 airfoil at an angle of attack alpha = 3 deg. and freestream Mach number of M-infinity = 0.3. Different Reynolds numbers are analyzed spanning 0.5 x 10(5) <= Re <= 4 x 10(5). Results show that the flow patterns responsible for noise generation appear from different laminar separation bubbles, including one observed over the airfoil suction side and another near the trailing edge, on the pressure side. For lower Reynolds numbers, intermittent vortex dynamics on the suction side results in either coherent structures or turbulent packets advected towards the trailing edge. Such flow dynamics also affects the separation bubbles on the pressure side, which become intermittent. Despite the irregular occurrence of laminar-turbulent transition, the noise spectrum depicts a main tone with multiple equidistant secondary tones. Increasing the Reynolds number leads to a permanent turbulent regime on the suction side that reduces the coherence level causing only small scale turbulent eddies to be observed. Furthermore, the laminar separation bubble on the suction side almost vanishes while that on the pressure side becomes more pronounced and permanent. As a consequence, the dominant noise generation mechanism becomes the vortex shedding along the wake. (AU) | |
| FAPESP's process: | 18/11835-0 - Numerical investigation of aircraft landing gear noise |
| Grantee: | Tulio Rodarte Ricciardi |
| Support Opportunities: | Scholarships in Brazil - Doctorate |
| FAPESP's process: | 13/08293-7 - CCES - Center for Computational Engineering and Sciences |
| Grantee: | Munir Salomao Skaf |
| Support Opportunities: | Research Grants - Research, Innovation and Dissemination Centers - RIDC |
| FAPESP's process: | 21/06448-0 - High-fidelity numerical simulations applied in unsteady aerodynamics, turbulence and aeroacoustics |
| Grantee: | William Roberto Wolf |
| Support Opportunities: | Research Grants - Young Investigators Grants - Phase 2 |