Large-Eddy Simulation of a Round Jet in Crossflow

A numerical simulation of a round turbulent jet issuing perpendicularly into a laminar M = 0.2 boundary-layer crossflow is performed at a jet-to-crossflow momentum ratio of 3.3 and a jet Reynolds number of 6930. The mixing behavior of the jet in crossflow is investigated by computing the evolution of a passive scalar. The spatial discretization of the computational domain consists of a block-structured multiblock grid with 58 blocks and a total of 8.9 million cells. The NSMB (Navier-Stokes Multiblock) simulation code uses a finite-volume discretization with a skew-symmetric fourth-order central scheme and a four-stage Runge-Kutta method for time integration. To account for the subgrid scales, the approximate-deconvolution model is employed in a multiblock formulation. Of special interest is the mixing behavior of the jet with the crossflow connected with the complex vortex systems in the mixing region. Results are compared with incompressible large-eddy simulation data and experimental measurements at similar flow parameters. Significant findings comprise the study of the jet development along its trajectory, as well as the upstream influence of the crossflow into the nozzle. Furthermore, the three-dimensional temporal oscillation of the ejected jet body is investigated and an attempt is made to correlate it to the formation of vortices in the mixing region.