Influences of Triangular Groove Geometry on Mixing Behavior of an Axisymmetric Supersonic Jet

The current investigation investigates the supersonic jets’ mixing characteristics without and with grooves of triangle shape. Computationally, a convergent–divergent nozzle of 1.73 exit Mach number accommodated with a passive control technique as triangular grooves is studied. The decay characteristic of supersonic jet and flow evolution for a plain nozzle and a nozzle with triangular grooves are discussed. Furthermore, it is discovered that the realizable k-ε turbulence model effectively captures the structure of supersonic jet. In overexpanded jets, the grooves produce extra compression waves near the beginning of the grooves, which causes the vortices formed from the grooves to turn toward the jet axis, causing huge deformities in the structure of jet, as well as substantial lateral spread and mass entrainment. The triangular grooves achieve a maximum decay in supersonic core length of 33.3%, which is case of correctly expanded case. For overexpanded and underexpanded jets, the decrement in length of supersonic core for triangular grooves is 21.4% and 28.6%, respectively.