Experimental Study of Strut Insertion Technique in a Convergent-Divergent Nozzle for Thrust Vector Control

The purpose of this paper is to present the findings from the data obtained from experiments conducted on a solid strut insertion technique with a convergent-divergent nozzle and to assess the possibility of this technique as an alternative thrust vector control technique. Independent and inceptive experiments were conducted to obtain supersonic nozzle wall pressure distributions by inserting a solid strut in the wall at two different positions from the nozzle throat in the diverging section of the nozzle. Experimental investigation was conducted using a convergent-divergent nozzle of design Mach number 1.8 at an inlet total pressure of 690 kPa (under-expansion conditions). The strut height was varied to obtain wall pressure distributions on both strut and opposite to strut sides. Forces and moments generated by the asymmetrical wall pressure distribution in a plane through the wall pressure ports on either side of the nozzle axis were calculated. From the wall pressure distributions corresponding to each strut height, the side force, and axial force and pitching moment coefficients (2D) were calculated. The variations of side force and pitching coefficients with respect to strut height were nonlinear and that to axial force were more or less linear. The present experimental study will help design and develop a solid strut insertion-based thrust vector control technique for aerospace flight vehicles.