Characteristics of Separation at Conical Afterbodies

The mean-flow and turbulence characteristics of motion following separation from a conical afterbody were investigated for various combinations of initial boundary-layer thickness and angle of convergence of the boundary. For a given boundary geometry, the rate of turbulence production increases with decrease in the value of the boundary-layer thickness, and the increasing importance of the inertial effects of turbulence causes similarity profiles to be achieved earlier. For a given boundary-layer thickness, the flow characteristics remain almost unchanged for cone angles greater than 60○. When the cone angle is progressively reduced to 50○, the rate of turbulence production increases and the size of the eddy pocket decreases. On reattachment of the separation profile to the boundary of the tailpiece, any further reduction in the cone angle causes the cumulative turbulence production to decrease continuously.