Sensing wall-pressure fluctuations by particle image velocimetry

Fulvio Scarano , Sina Ghaemi

The use of particle image velocimetry (PIV) to measure the instantaneous pressure field and in particular the pressure at solid boundaries is discussed. The method is based on the use of time-resolved PIV measurements combined with the evaluation of the momentum equation to solve for the pressure gradient and its subsequent spatial integration. In principle, the application of this technique is straightforward, but it requires a careful assessment of error propagation. In exchange, the method offers the potential to measure pressure fluctuations over a very wide range of flow regimes as demonstrated by experiments performed on bluff-body flows (de Kat and van Oudheusden, 2011) and cavities (Haigermoser, 2009). In two-dimensional unsteady flows, the fluctuating pressure distribution evaluated at the surface is used as input for the evaluation of acoustic pressure fluctuations making use of Curle's analogy, in cavity flow experiments (Kostchatzky et al., 2011) and to predict the noise emissions from a rod-airfoil system (Lorenzoni et al., 2009). From recent experiments with tomographic PIV the accuracy and reliability of such approach has also been established for broadband pressure fluctuations as they occur in turbulent boundary layers (Ghaemi and Scarano, 2012) and more prominently at the trailing edge of airfoils.

Domaines: Acoustique [physics.class-ph]

Fulvio Scarano, Sina Ghaemi. Sensing wall-pressure fluctuations by particle image velocimetry. Acoustics 2012, Apr 2012, Nantes, France. ⟨hal-00811394⟩