Three-dimensional numerical simulations for the jet flow field of separate flow nozzles with/without chevrons on core nozzle were carried out.Calculation was conducted by employing second order upwind discretization scheme and RNG(renormalization group) k-ε turbulent model.As compared with baseline axisymmetric separate flow nozzle

addition of chevrons can strengthen the jet mixing since chevrons introduce streamwise vortices and increase the length of the mixing layer between core stream and fan stream

resulting in obvious reduction of hot potential core length and the decay of jet maximum velocity near the centerline.Moreover

increment of chevron deflection angle greatly enhances vortex strength so as to decrease jet velocity and total temperature substantially in a certain axial range.Relatively

reinforcement of jet mixing with increment of chevron length is not evident.