Passive scalar mixing in a spatially developing shear layer: Comparison of one-dimensional turbulence simulations with experimental results

One-dimensional turbulence (ODT) simulations of a spatially developing planar shear layer are used to obtain the probability density function (PDF) of the concentration of a passive scalar. An asymmetry of the PDF with respect to transverse location in this self-similar flow appears in the ODT results and in experimental results obtained with planar laser-induced fluorescence of acetone. Using the ODT simulations, estimates are presented of the effect of measurement volume upon the resulting PDFs. Variable density effects on the concentration of the denser fluid within incompressible flow are also examined.