Flow and Performance Analysis of Annular Cluster Truncated Plug Nozzle

Four different length annular cluster truncated plug nozzle flowfields have been analyzed, using both experimental and computational tools, for pressure ratios ranging from 5 to 85, which includes the transition of an open base wake to a closed base wake. The flow expansion on the plug surface has been discussed with respect to streamwise and azimuthal directions. The presence of shock structure and vortical pattern of the streamlines downstream of the splitter plate are discussed. For the base pressure analysis, the cluster truncated plug nozzle results have been compared with the corresponding length plug nozzle in which the primary nozzle is not a clustered one. The average base pressure and wake transition pressure ratio of these nozzles have been presented, and the limitations of the present-day computational and empirical tools in predicting the same have been discussed. In addition, the performance of the nozzle with regard to the contribution of each component toward thrust has been brought out