Numerical study of secondary mass flow modulation in a Bypass Dual-Throat Nozzle

Hamedi-Estakhrsar, M. H.; Ferlauto, Michele; Mahdavy-Moghaddam, Hossein

doi:10.1177/0954410020947920

Cited by 8 publications

(10 citation statements)

References 33 publications

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“…RANS approach has been employed in several investigations related to the dual-throat nozzles among which references (Hamedi et al 2020aand 2021b, Gu et al 2014, and Deere and Karen. 2003) can be mentioned as some examples.…”

Section: Governing Equationsmentioning

confidence: 99%

Computational Investigation of Effects of Side-Injection Geometry on Thrust-Vectoring Performance in a Fuel-Injected Dual Throat Nozzle

2022

JAFM

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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.

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Section: Governing Equationsmentioning

confidence: 99%

Computational Investigation of Effects of Side-Injection Geometry on Thrust-Vectoring Performance in a Fuel-Injected Dual Throat Nozzle

2022

JAFM

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“…Until now, the effect of secondary mass flow modulation, expansion ratio, cavity radius, nozzle throat radius, dynamic vector rate, and dynamic hysteresis time has been investigated in detail. [17][18][19][20][21][22] However, the contribution of nozzle convergence angle with bypass width and bypass angle with bypass width on the bypass dual throat nozzle (BDTN) performance is still unknown. Based on the literature, a BDTN is selected to study the thrust vectoring behavior of the nozzle.…”

Section: Motivation and Organization Of Researchmentioning

confidence: 99%

“…Results indicate that the numerical model can resolve the detailed flow field and that the experimental and numerical results agree well. [17][18][19][20][21][22] Therefore, in the present work, FLUENT is used to solve the governing equations with RNG k-ϵ turbulence modeling to simulate the flow through the proposed geometry configurations. The governing equations including conservation of mass, momentum, and energy equations are written as follows 29 :…”

Section: Computational Fluid Dynamics Flow Solvermentioning

confidence: 99%

Multi-objective nozzle design optimization for maximum thrust vectoring performance

Afridi

Khan

2022

Proceedings of the Institution of Mechanical Engineers, Part G:

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Thrust vectoring is a promising technology that offers the potential for improved maneuverability, control efficiency, and stealth characteristics of aircraft. Optimized nozzle design over a range of operating conditions is one of the most crucial factors for maximum thrust vectoring operation. Our goal was to investigate the optimal design of bypass dual throat nozzle to maximize thrust vectoring. We performed a multi-objective optimization study by varying the nozzle bypass angle, convergence angle, and bypass width to see what impact these parameters had on the performance of the bypass dual throat nozzle. A steady numerical simulation has been performed on 55 different nozzle configurations to compare their thrust vectoring performance and losses. In all simulations, the k- ϵ turbulence model is used to determine the vectoring states of the nozzle. The computational fluid dynamics analysis was followed by a multi-objective optimization process using the Response Surface Methodology within the ModeFrontier software. The testing of the optimized nozzle shapes using ANSYS FLUENT verified the accuracy and reliability of the multi-objective optimization algorithm. These findings suggest that nozzle convergence does not significantly affect thrust vectoring. In contrast, bypass width and bypass angle significantly affected thrust vectoring.

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“…ANSYS Fluent 2020 R2 is used for calculation. The solver type of the density-based solver is used here, which is different from the pressure-based solver used by Hamedi-Estakhrsar et al [21]. The density-based solver couples mass, momentum, and energy equations together to obtain an accurate solution.…”

Section: Domain and Boundary Conditionsmentioning

confidence: 99%

“…Hamedi-Estakhrsar and Mahdavy-Moghaddam [20] further computationally and experimentally investigated the influence of NPR and different positions of the bypass passage on the three-dimensional (3-D) rectangular BDTN performance and illuminated the configuration with bypass passage at the upstream nozzle throat has the largest vectoring angle for all values of NPR. Subsequently, Hamedi-Estakhrsar et al [21] proposed a kind of mass flow modulation technology for a BDTN and applied it to the V-shaped bypass.…”

Section: Introductionmentioning

confidence: 99%

A fluidic thrust vector control using the bypass flow in a dual throat nozzle

Kim

2021

J Mech Sci Technol

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The present study is to explore an active mass flow control technology for an emerging bypass dual throat nozzle. A new arc-shaped bypass system has been applied to replace the previous V-shaped bypass for the bypass dual throat nozzle, which can decrease the total pressure loss significantly. The bypass passage has a contraction part with a variable area ratio. The vector control effectiveness is discussed with different contraction area ratios of the bypass passage. The obtained results reveal that friction choking and geometry choking play crucial roles to affect the bypass mass flow, respectively. When the bypass passage is fully open, the choking location of the bypass flow occurs at the bypass exit, owing to the viscous boundary layer along the constant area passage. A contraction area ratio less than 0.5 does not change the choking position of the bypass flow, because the viscous boundary layer is larger than the geometry contraction height. While the contraction area ratio reaches or exceeds 0.5, the geometry choking takes place in the contraction section. The vectoring angle and bypass mass flow ratio decrease with an increase in the contraction area ratio, whereas thrust coefficient, thrust efficiency, and total pressure loss increase.

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Numerical study of secondary mass flow modulation in a Bypass Dual-Throat Nozzle

Cited by 8 publications

References 33 publications

Computational Investigation of Effects of Side-Injection Geometry on Thrust-Vectoring Performance in a Fuel-Injected Dual Throat Nozzle

Computational Investigation of Effects of Side-Injection Geometry on Thrust-Vectoring Performance in a Fuel-Injected Dual Throat Nozzle

Multi-objective nozzle design optimization for maximum thrust vectoring performance

A fluidic thrust vector control using the bypass flow in a dual throat nozzle

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