Experimental Investigation of the Effect of Location of Cylindrical Protuberance on the Thrust Vector of a Supersonic C-D nozzle

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 C-D nozzle was designed and constructed. The nozzle exit Mach number is 2. The wall of the nozzle is equipped with pressure holes to measure pressure variations. Also, there are several holes in the divergence portion of nozzle wall to apply a protuberance inside the nozzle. Pressure sensors for pressure measurement and also the Schliern system are used to check the outlet flow field. The nozzle pressure ratio in all experiments is constant and in two cases is equal to NPR=6.6 and NPR=9. The protuberance is installed in the nozzle divergence section, at position X⁄L=0.6,0.7,0.8,0.9 and with a constant penetration ratio of H⁄D^* =0.2. The results of this study show that using the protuberance can control the angle of the thrust vector. Also, installing location X⁄L=0.9 is the best position which, in this case the angle of the trusted vector reaches 3.1 degrees. Also, the results reveals that the change in the nozzle pressure ratio in different installing positions has different effects on the thrust vector angle and axial thrust losses.