Report presenting an investigation to determine the pressure drag of various blunt-based conical afterbodies at a range of Mach numbers. A generalized series of bodies was included which incorporated convergent nozzles discharging unheated jets at various pressures from the base. Results regarding the afterbodies without the jet and afterbodies with the jet are provided.

Report presenting an investigation of a shock-positioning control on a 16-inch ramjet engine at a range of Mach numbers and angles of attack in the supersonic wind tunnel. The control operated at all conditions under which the engine could be manually operated. Prediction of the control-system dynamic behavior can be applied by treating the system as having pure dead time.

Report presenting an investigation of the screeching characteristics of two flame-holder configurations in a full-scale transpiration-cooled afterburner. The investigation indicated that a porous wall of wire cloth may be effective in eliminating or reducing the tendency to screech in some high-performance afterburners, but further testing is required. Results regarding the diametrical V-gutter, single-ring V-gutter, and durability of wire cloth are provided.

Report presenting experiments conducted on conical convergent-divergent nozzles having included a range of divergence angles and expansion ratios over a wide range of nozzle pressure ratios with cold flow to determine the effect of divergence angle on the internal performance of the nozzles. Results regarding the performance characteristics, effect of divergence angle on overexpanded performance, and effect of divergence angle on nozzle air-flow characteristics are provided.

Report presenting an investigation of a shock-positioning control on a 16-inch ramjet engine at a range of Mach numbers and angles of attack in a supersonic wind tunnel. The static-pressure rise across the inlet normal shock was utilized in setting the diffuser at its critical condition. Results regarding the sensing pressures, engine performance, control set engine operation, pressure data, operation of the control during Mach number change, and other applications of control are provided.