Turbulent flow field analysis of a jet in cross flow by DNS

The turbulent flow field induced by a round jet in crossflow is calculated by parallel direct numerical simulation (DNS) on multi-GPU clusters. The DNS is based on the lattice- Boltzmann method. With current GPU settings, a grid system of 1.5 × 108 is adopted and the largest jet Reynolds number reaches 3000. The jet is orthogonal to the mainstream flow direction. The validated code produces good agreements with theory and experiment. Steady and unsteady vortical structures are presented based on velocity fields and vorticity distributions. Profiles of Reynolds stress components are also displayed and analyzed. Hair-pin coherent structures are presented based on second invariant of velocity gradient. Transport of turbulent kinetic energy is represented by budget terms in x-, y- and z-direction planes and along the leading and trailing edges of jet trajectory.