Preliminary Analysis and Design Enhancements of a Dual-Throat FTV Nozzle Concept

Bellandi, Erik; Slippey, Andrew

doi:10.2514/6.2009-3900

Cited by 10 publications

(9 citation statements)

References 6 publications

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“…1 Since the 1990 s, several concepts of fluidic thrustvectoring nozzles have been introduced and researched: shock vector control nozzle, [3][4][5] counterflow nozzle, 6,7 throat shifting nozzle, 8,9 and dual throat nozzle (DTN). [10][11][12][13][14][15][16][17][18] The shock vectoring control nozzle can provide large thrust-vector angles but lose much system thrust because of the strong shock waves. [3][4][5] The counterflow nozzle can also acquire large thrust-vector angles but certain problems (e.g.…”

Section: Introductionmentioning

confidence: 99%

“…15,16 However, the results of this study demonstrated that the thrust efficiency of the nozzle was not enhanced because of the normal shock wave located in the cavity. Other computational and experimental researches were also executed [17][18][19] and a twodimensional (2D) divergent DTN was investigated to acquire large thrust vector angles. [19][20][21] For the divergent DTN, as the NPR increases, the normal shock wave begins to appear and moves downstream, but remains inside the cavity.…”

Section: Introductionmentioning

confidence: 99%

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Experimental and numerical investigation of an axisymmetric divergent dual throat nozzle

Wang

Huang

et al. 2019

Proceedings of the Institution of Mechanical Engineers, Part G:

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The dual throat nozzle achieves higher thrust vectoring efficiencies and lesser thrust loss than other fluidic thrust-vectoring nozzles. Separation always occurs at the bottom of the cavity with complex three-dimensional characteristics for the dual throat nozzle. In this paper, by comparing the flow structure, nozzle surface static pressure distributions and skin friction lines, which are obtained by numerical simulations and wind tunnel experiments, an axisymmetric divergent dual throat nozzle is investigated in detail. The main results show the following findings. (1) The experimental schlieren photographs confirm again that the divergent nozzle configuration has the starting problem from an intuitive perspective. Meanwhile, the flow structure and nozzle surface static pressure distributions obtained by numerical simulations are consistent with the experimental results, except for the low nozzle pressure ratios. (2) The circumferential pressure difference is negligible upstream of the separation line but obvious downstream of the separation line. The skin friction lines and nozzle surface static pressure distributions of different circumferential angles obtained by experiments both prove that the actual flow in the axisymmetric divergent dual throat nozzle indeed possesses three-dimensional characteristics. Therefore, it is necessary to utilize the full three-dimensional computational domain to study the complex three-dimensional characteristics of the flow for the axisymmetric divergent dual throat nozzle thoroughly.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Experimental and numerical investigation of an axisymmetric divergent dual throat nozzle

Wang

Huang

et al. 2019

Proceedings of the Institution of Mechanical Engineers, Part G:

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“…Catt and Miller (1995, 2001 investigated flow characteristics of a TS nozzle, obtained a δp of 8º, a thrust coefficient (Cfg) of 0.94 and a vector efficiency of 1.7-2.0º/% (that is vector angle of 1.7º-2.0º with per 1% secondary flow) at low NPR, but as studied by Zhang (2012), the vector performance of TS method is lower than SVC method at higher NPR (NPR>6.24). The DTN TV involves a convergent-divergent nozzle (Deere, et al 2005;Bellandi, et al 2009). A vector angle is generated by injecting secondary flow upstream of throat which causes flow separation in the recessed cavity between the two geometric minimum areas.…”

Section: Introductionmentioning

confidence: 99%

Investigation on Flow Characteristics of SVC Nozzles

Jingwei¹,

Wang²,

et al. 2018

JAFM

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Shock vectoring control (SVC) is an important method of fluidic thrust vectoring (FTV) for aero-engine exhaust system. It behaves better on nozzle of high pressure ratio, and is considered as an alternative TV technology for a future aero-engine with high thrust-to-weight ratio. In this paper, the flow mechanism and vector performance, including the vector angle (δp) and thrust coefficient (Cfg), of 2D and axisymmetric SVC nozzles were investigated after the validation of turbulence models by experimental data. The influence of aerodynamic parameters, e.g. nozzle pressure ratio (NPR), secondary pressure ratio (SPR) and free-stream Ma number (M∞) on flow characteristics and vector performance were studied numerically, and results show that unbalanced pressure distributions on nozzle internal walls determine δp, while shock waves dominate thrust loss, referring to Cfg. The "pressure release mechanism" of an axisymmetric SVC nozzle causes vector angle about 16.54% smaller than that of a 2D SVC nozzle at NPR of 6. The induced shock wave interacts with nozzle upper wall at SPR of 1.5, and results in the δp of a 2D SVC nozzle 12% smaller. A new parameter (Fy,modi) of side-force was redefined for free-stream conditions, taking the pressure distributions on nozzle external walls into account. Results indicate that pressure connection on nozzle external walls of an axisymmetric SVC nozzle causes vector performance better at M∞ >0.3 and the δp is about 11.2% larger at transonic conditions of M∞ of 0.9 and 1.1.

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“…(9)(10)(11)(12)] are a simplification of the suction/ blowing model derived in [22] and are similar to the BCs for the flow inlet [28].…”

Section: Mathematical Modelmentioning

confidence: 99%

“…According to Flamm et al [11], the best thrust-vectoring performance is obtained when the two minimum areas are equal. Recently, other numerical and experimental investigations [12][13][14] have been performed, and new DTN optimal geometries have been suggested.…”

mentioning

confidence: 99%

Numerical Investigation of the Dynamic Characteristics of a Dual-Throat-Nozzle for Fluidic Thrust-Vectoring

Ferlauto

Marsilio

2017

AIAA Journal

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A computational method tailored for the simulation of fluidic thrust-vectoring systems is employed to investigate the dynamic response of a dual-throat nozzle in open-and closed-loop control. Thrust vectoring in fixed, symmetric nozzles is obtained by secondary flow injections that cause local flow separations, asymmetric pressure distributions, and, as a consequence, the vectoring of primary jet flow. The computational technique is based on a well-assessed mathematical model for the compressible unsteady Reynolds-averaged Navier-Stokes equations. A minimal control system governs the unsteady blowing. Nozzle performances and thrust-vector angles have been computed for a wide range of nozzle pressure ratios and secondary flow injection rates. The numerical results are compared with the experimental data available in the open literature. Several computations of the open-loop dynamics of the nozzle under different forcing have been performed to investigate the system response in terms of thrust-vectoring effectiveness and controllability. These computations have been used to extract autoregressive exogenous models of the nozzle dynamics. The effects of including the actuator dynamics are also discussed. Simple strategies of closed-loop control of the nozzle system by proportional-integrative-derivative regulators are investigated numerically. The closed-loop model predictive control of the system, based on the autoregressive exogenous models, is addressed.

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Preliminary Analysis and Design Enhancements of a Dual-Throat FTV Nozzle Concept

Cited by 10 publications

References 6 publications

Experimental and numerical investigation of an axisymmetric divergent dual throat nozzle

Experimental and numerical investigation of an axisymmetric divergent dual throat nozzle

Investigation on Flow Characteristics of SVC Nozzles

Numerical Investigation of the Dynamic Characteristics of a Dual-Throat-Nozzle for Fluidic Thrust-Vectoring

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