Measurement of a Benchmarking Jet in Crossflow Configuration Under Highly Turbulent Conditions

The configuration of a jet in crossflow appears in many practical applications such as combustion and mixing processes in the chemical industry. This kind of flow is particularly complex due to the presence of various interacting vortex systems and it is widely studied in literature both experimentally and numerically. In addition to the physical interest, this flow configuration serves as a benchmark for numerical methods such as Direct Numerical Simulations (DNS) and Large Eddy Simulations (LES) because of its prototypic nature. The present work aims at generating benchmark data for a jet in crossflow configuration under highly turbulent conditions. In this context, the investigated operating conditions were chosen carefully to match the conditions existing in gas turbines and hence the experiments were carried out for two different Reynolds-numbers of the crossflow, Re_∞ = 60000 and 40000. Keeping the flow rate of the jet flow constant, two different velocity ratios between jet and crossflow of r = 4.15 and 6.25 result. The measurements were performed in an appropriate air channel, which was built with the objective to obtain accurately controlled flow conditions at the measurement section. Two-dimensional laser induced fluorescence (2d-LIF) combined with particle imaging velocimetry (PIV) was used for the measurements of simultaneous scalar concentration and velocity fields and the experimental acquisition of Reynolds-fluxes and -stresses. The knowledge of Reynolds-fluxes and -stresses is of fundamental concern not only for the understanding of the mechanisms which are responsible for the formation of the vortex-structures in a jet in crossflow, but also for the development and validation of turbulence- and mixing-models.