Material acceleration determination for high speed flows by means of Shake-The-Box multi-pulse particle tracking

Kurzfassung

The measurement of the instantaneous pressure field is of interest for many engineering applications ranging from noise generation to aerodynamic loads determination. Recently, several approaches based on particle image velocimetry data have been proposed in order to measure the fluid velocity material derivative and, subsequently, the local pressure gradient via the momentum equation (van Oudheusden 2013). The advantage of these approaches with respect to the use of pressure transducers or pressure sensitive paint resides in the non-intrusive nature of the particle imaging based technique able to deliver a high number of measurement points in a planar or even volumetric domain. Eulerian and pseudo-Lagrangian approaches have been investigated, where the acceleration is inferred starting from velocity vector fields obtained by cross-correlation of 3D reconstructed objects from tomographic-PIV (Tomo-PIV, Elsinga et al 2006). On the other hand, the Shake-the-Box particle tracking technique (STB, Schanz et al 2016) is capable of accurately reconstructing single particle tracks over long time sequences at high seeding density, avoiding the signal modulation and filtering introduced by the cross-correlation based methods and offering direct access to the Lagrangian properties of the fluid. The STB technique has been proposed for time-resolved data, typically available for low speed flows (<10