Experimental 3D fields of velocity, density, and pressure in variable-density turbulent flows

Understanding the physics of variable-density (VD) turbulence and validation of the relevant turbulent models desperately require experimental data providing the 3D structures of velocity, density, and pressure at the same time. Unfortunately, the simultaneous application of tomographic techniques for both velocity and density is currently too expensive and challenging. In this context, we recently developed a new reconstruction algorithm for generating time-resolved 3D velocity and density fields from simultaneous stereoscopic particle image velocimetry and laser-induced fluorescence. This new method has been demonstrated to be more accurate in turbulent shear flows than the more frequently used method based on the Taylor's hypothesis of frozen turbulence. The improvements in the 3D velocity and density reconstructions also enable the possibility of recovering more accurate 3D pressure fields. Using this method, we present time-series of experimental 3D velocity, density, and pressure fields of a VD round jet. This dataset can then provide crucial information on the pressure-density-velocity correlation statistics, shedding light on the effects of density gradients on the pressure transport of turbulent kinetic energy and on the evolution of turbulent anisotropy in space.