Pressure Field Estimates in a Three-Dimensional Turbulent Wall Jet

Low-order estimates of turbulent velocity fields are useful for understanding large-scale motions in turbulent flows. The use of these estimates for the calculation of coupled quantities such as the hydrodynamic pressure however has not been fully evaluated in terms of the quantitative features that are reproduced in many three-dimensional flows. In this work, 16 individual spanwise aligned particle image velocimetry measurement planes of an aspect ratio 8 wall jet are independently obtained, synchronously with 32 surface pressure transducer measurements. An estimate of the three-dimensional velocity field is calculated via modified stochastic estimation and used to solve Poisson's equation for pressure fluctuations throughout the measurement ``volume.'' The large scale vortical motion captured by the velocity estimates result in convecting, intermittent positive and negative pressure regions throughout the wall jet. The estimated surface pressure spectrum captures similar features as the measurements in the most energetic portion of the spectrum and matches measured spectral magnitudes well in the region impacted by the breakdown of the jet core where the near wall region is impacted by the large scale motion. Knowledge of the pressure field also allows for the calculation of pressure related terms from the Reynolds stress transport equation, which can be of use in the construction of turbulence models.