Large-Eddy Simulations and Measurements of a Small-Scale High-Speed Coflowing Jet

Measurements and predictions are made of a short-cowl coflowing jet with a bypass ratio of 8:1. The Reynolds number is 300,000, and the inlet Mach numbers are representative of aeroengine conditions. The low Reynolds number of the measurements makes the case well suited to the assessment of large-eddy-simulation-related strategies. The nozzle concentricity is carefully controlled to deal with the emerging metastability issues of jets with coflow. Measurements of mean quantities and turbulence statistics are made using both laser Doppler anemometry and particle image velocimetry. The simulations are completed on 6 x 10(6), 12 x 10(6), and 50 x 10(6) cell meshes. To overcome near-wall modeling problems, a hybrid large-eddy-simulation Reynolds-averaged-Navier Stokes-related method is used. The near-wall Reynolds-averaged-Navier Stokes layer is helpful in preventing nonphysical separation from the nozzle wall.