DOI: 10.1615/TSFP9
TURBULENT SCALAR MIXING IN A SKEWED JET IN CROSSFLOW: EXPERIMENTS AND MODELING
ABSTRACT
Turbulent mixing of an inclined, skewed jet injected into a crossflow is investigated using MRI-based experiments and a high-fidelity LES of the same configuration. The MRI technique provides three-dimensional fields of mean velocity and mean jet concentration. The 30° skew of the jet relative to the crossflow produces a single dominant vortex which introduces spanwise asymmetries to the velocity and concentration fields. The turbulent scalar transport of the skewed jet was investigated in further detail using the LES, which was validated against the experimental measurements. Mixing was found to be highly anisotropic throughout the jet region. Isotropic turbulent diffusivity and viscosity were used to calculate an optimal value of the turbulent Schmidt number, which varies widely over the jet region and lies mostly outside of the typically accepted range 0.7 ≤ Sct ≤ 0.9. Finally, three common scalar flux models of increasing complexity were evaluated based on their ability to capture the anisotropy of the present configuration. The higher order models were shown to better represent the turbulent scalar flux vector.