Jet Vectoring performances of ten different designs with various depths and geometrical outlines were quantified through constant temperature anemometry measurements for a Reynolds number range from 10, 000 to 30, 000 by using passive and active flow control methods at cold flow. The reference design was based on NASA’ s double throat nozzle concept and a self-injection double throat nozzle design that uses similar flow control concept as the reference design, were also tested for performance comparison. Furthermore, jet Vectoring performance of a single throat design, utilizing Coanda effect for jet Vectoring, was also quantified. Results indicated jet Vectoring angles starting from 2° up to 47° for a control jet flow rate range from 1% up to 10% with respect to the primary jet flow rate in the investigated Re range. Maximum jet Vectoring angle was achieved with a single throat design which incorporates small step geometry before the Coanda surface for more effective flow attachment and these results were compared with the Vectoring performance of the double throat nozzle designs.

A computational investigation was conducted to optimize the fluidic injection angle effects on thrust Vectoring. Numerical simulation of fluidic injection for shock vector control, with a convergent-divergent nozzle concept was performed, using URANS approach with Spalart-Allmaras turbulence model. The fluidic injection angles from 60º to 120º were investigated at different aerodynamic and geometric conditions. The current investigation demonstrated that secondary injection angle is an essential parameter in fluidic thrust Vectoring. Computational results indicated that, optimizing secondary injection angle would have positive impact on thrust Vectoring performance. Furthermore, in most cases, decreasing expansion ratio of the nozzle with increasing NPR has negative impact on pitch thrust vector angle and thrust Vectoring efficiency. That is, the highest pitch thrust vector angle is obtained by decreasing nozzle expansion ratio with increasing SPR in smaller fluidic injection angles. In addition, the current investigation attempted to initiate a database of optimized injection angles with different essential parameter effects on thrust Vectoring, in order to guide the design and development of an efficient propulsion system.

Dual-throat Nozzle (DTN) is known as one of the most effective approaches of fluidic thrust-Vectoring. It is gradually flourishing into a promising technology to implement supersonic and hypersonic thrust-vector control in aircrafts. The main objective of the present study is numerical investigation of the effects of secondary injection geometry on the performance of a fuel-injected planar dual throat thrust-Vectoring nozzle. The main contributions of the study is to consider slot and circular geometries as injector cross-sections for injecting four different fuels, moreover, the impact of center-to-center distance of injection holes for circular injector is examined. Three-dimensional compressible reacting simulations have been conducted in order to resolve the flowfield in a dual throat nozzle with pressure ratio of 4. 0. Favre-averaged momentum, energy and species equations are solved along with the standard k-ε model for the turbulence closure, and the eddy dissipation model (EDM) for the combustion modelling. Second-order upwind numerical scheme is employed to discretize and solve governing equations. Different assessment parameters such as discharge coefficient, thrust ratio, thrust-vector angle and thrust-Vectoring efficiency are invoked to analyze the nozzle performance. Computationally predicted data are agreed well with experimental measurements of previous studies. Results reveal that a maximum vector angle of 17. 1 degrees is achieved via slot injection of methane fuel at a secondary injection rate equal to 9% of primary flow rate. Slot injection is performing better in terms of discharge coefficient, thrust-vector angle and thrust-Vectoring efficiency, whereas circular injection provides higher thrust ratio. At 2% secondary injection for methane fuel, vector angle and Vectoring efficiency obtained by slot injector is 8% and 34% higher than the circular injector, respectively. Findings suggest that light fuels offer higher thrust ratio, vector angle and Vectoring efficiency, while heavy fuels have better discharge coefficient. Increasing center-to-center distance of injector holes improves thrust ratio, while having a negative effect on discharge coefficient, vector angle and Vectoring efficiency. A comparison between fuel injectant of current study and inert injectant in the previous studies indicates that fuel reaction could exhibit substantial positive effects on Vectoring performance. Secondary-to-primary momentum flux ratio is found to play a crucial role in nozzle performance.

In the realm of aviation, jet propulsion systems serve to provide enhanced maneuverability and to make sure that the aircraft thrust is accurately and precisely regulated during take-off and landing operations. The movement of aerodynamic control surfaces (flaps, slats, elevators, ailerons, spoilers, wing attachments) determines the mobility of practically all aircraft types. Recognized as dependable components in the aviation world for take-off and landing tasks, these control surfaces are being replaced by fluidic thrust Vectoring (FTV) systems, especially in small unmanned aerial vehicles (UAVs) and short or vertical take-off and landing aircraft. The FTV system is capable of directing thrust in any preferred direction without the need for any movable components. This paper numerically examines the FTV system by utilizing computational fluid dynamics (CFD) and an optimization technique based on gradients of the system components to understand the physics of the Coanda effect in FTV systems. This research employs gradient-based optimization for nozzle design in order to optimize the parameter space for different velocity ratios (VR) by calculating the moment around the upper Coanda surface, which is used to represent the jet deflection angle. In that context, four different Coanda surface-pintle pair designs for four different VRs are produced. The parameter space shows significant improvement in all four configurations, and results reveal that all output parameters successfully delay separation on the thrust Vectoring system's upper Coanda surface. Finally, four optimum design suggestions are tested at various VRs, and the most efficient and proper design is recommended based on output parameters.