Experimental Investigation of the Effect of Cylindrical Protuberance with Different Penetration on the Thrust Vector a C-D Nozzle in Supersonic Regime

In this study, the effect of a cylindrical protuberance on the thrust vector of a supersonic jet was investigated as a new method in thrust vector control. For this purpose, a convergent-divergent (C-D) nozzle was designed and constructed. This nozzle is such that the Mach number is its nominal output in full expansion conditions 2. The wall of the nozzle is equipped with pressurized holes to measure pressure variations. Also, there is a duct wall in the nozzle wall to apply a protuberance inside the nozzle. Pressure sensors are used for pressure measurement and also the schlieren system IS used to check the outlet flow field. The total pressure of the compartment is constant at all tests and is 5.7 bar. The results of this study show that the depth of penetration of the protuberance in the flow field has a significant effect on the amount of deviation and even the direction of the deviation of the jet stream exited from the C-D nozzle. The maximum jet outlet flow from the nozzle is 5.7 degrees, which occurred at a rate of H/D*=0.4. In addition, these results indicate that with the increase in bulge penetration within the nozzle, the nozzle axial thrust has slightly decreased.