Abstract
In aerodynamic and aeroacoustic research, pressure–velocity correlation and coherence have been increasingly utilised to identify and understand the motions of large scale structures and their collective effects on the surface pressure fluctuations due to the boundary layer. Nevertheless, when a relatively sharp transition from turbulent boundary layer to low turbulence free-stream takes place, it is observed that ‘spurious’ regions of elevated correlation and coherence level arise as a result of this transition and the use of conventional normalisation. The present study identifies this issue using measurements from a NACA 0012 airfoil and proposes a modified normalisation by taking the flow turbulence into account. The results have clearly demonstrated that the modified procedure helps successfully preclude these spuriously heightened p−u correlation and coherence regions.
Original language | English |
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Article number | 186 (2020) |
Number of pages | 7 |
Journal | Experiments in Fluids |
DOIs | |
Publication status | Published - 3 Aug 2020 |
Keywords
- Pressure velocity coupling
- cross-correlation analysis
- coherence analysis
- Aeroacoustics
- Aerodynamics