“…2, e.g., shock wave TVC (SWTVC), bypass shock wave TVC (BSWTVC), counterflowing TVC (COUTVC), coflowing TVC (COTVC), throat shifting TVC (TSTVC), dual throat nozzle TVC (DTNTVC), and bypass dual throat nozzle TVC (BDTNTVC). Wu and Kim (2019a; and Wu et al (2020c) carried through theoretical and computational fluid dynamics (CFD) work about steady features of the SWTVC in a supersonic rectangular propulsion nozzle and detailedly illuminated the impacts of injection-to-mainstream momentum flux ratio, injector location, and the length-to-width ratio of the slot injection syringe. Deng and Kim (2015) finished some CFD work concerning internal flow characteristics of the BSWTVC and elucidated the influences of nozzle pressure ratio (NPR) and injection-to-mainstream mass flow ratio, separately.…”
Section: Fig 1 Illustration Of Aircraft Axesmentioning
confidence: 99%
“…Other exit boundaries are taken as the pressure outlet boundary.All current CFD work is finished in the software of Fluent that is good at calculating incompressible and compressible flows based on pressure-based and density-based solvers(Lin et al 2020;Tao et al 2020;Wang et al 2019a;Wang et al 2019b). By referring to earlier references(Deng and Kim 2015;Vignesh et al 2016;Vignesh et al 2019;Wu and Kim 2019a;Raman et al 2020;Wu et al 2020a), the density-based solver is fixed for issues of compressible flow. The implicit formulation is used to address the equation system.…”
Compared to a variety of mechanical vectoring nozzles, fluidic vectoring nozzles possess more research value nowadays. The dual throat nozzle is gradually developing into an outstanding technology to handle supersonic and hypersonic aircraft deflections. Three-dimensional, steady, compressible, and viscous flows in rectangular dual throat nozzles are numerically investigated by resolving Reynolds-averaged Navier-Stokes equations and shear stress transport k-omega turbulence model. Computational fluid dynamics results are verified against the existing experimental data, where a good consistency is gained. The impacts of nozzle pressure ratio, injection-to-mainstream momentum flux ratio, and setup angle of the slot injector on the systemic performance are examined. Useful conclusions are summarized for engineering designers. Firstly, pitching angles decline along with an increasing nozzle pressure ratio, while systemic thrust ratio and thrust efficiency increase. Secondly, thrust vector angles enlarge with an increase of the injection-to-mainstream momentum flux ratio, whereas both systemic thrust ratio and thrust efficiency decay. Finally, the setup angle of the slot injector impacts the systemic performance remarkably. Although the pitching angle for the setup angle of 120° is highest, comprehensive characteristics in terms of systemic thrust efficiency and systemic thrust ratio for the setup angle of 150° are more excellent.
“…2, e.g., shock wave TVC (SWTVC), bypass shock wave TVC (BSWTVC), counterflowing TVC (COUTVC), coflowing TVC (COTVC), throat shifting TVC (TSTVC), dual throat nozzle TVC (DTNTVC), and bypass dual throat nozzle TVC (BDTNTVC). Wu and Kim (2019a; and Wu et al (2020c) carried through theoretical and computational fluid dynamics (CFD) work about steady features of the SWTVC in a supersonic rectangular propulsion nozzle and detailedly illuminated the impacts of injection-to-mainstream momentum flux ratio, injector location, and the length-to-width ratio of the slot injection syringe. Deng and Kim (2015) finished some CFD work concerning internal flow characteristics of the BSWTVC and elucidated the influences of nozzle pressure ratio (NPR) and injection-to-mainstream mass flow ratio, separately.…”
Section: Fig 1 Illustration Of Aircraft Axesmentioning
confidence: 99%
“…Other exit boundaries are taken as the pressure outlet boundary.All current CFD work is finished in the software of Fluent that is good at calculating incompressible and compressible flows based on pressure-based and density-based solvers(Lin et al 2020;Tao et al 2020;Wang et al 2019a;Wang et al 2019b). By referring to earlier references(Deng and Kim 2015;Vignesh et al 2016;Vignesh et al 2019;Wu and Kim 2019a;Raman et al 2020;Wu et al 2020a), the density-based solver is fixed for issues of compressible flow. The implicit formulation is used to address the equation system.…”
Compared to a variety of mechanical vectoring nozzles, fluidic vectoring nozzles possess more research value nowadays. The dual throat nozzle is gradually developing into an outstanding technology to handle supersonic and hypersonic aircraft deflections. Three-dimensional, steady, compressible, and viscous flows in rectangular dual throat nozzles are numerically investigated by resolving Reynolds-averaged Navier-Stokes equations and shear stress transport k-omega turbulence model. Computational fluid dynamics results are verified against the existing experimental data, where a good consistency is gained. The impacts of nozzle pressure ratio, injection-to-mainstream momentum flux ratio, and setup angle of the slot injector on the systemic performance are examined. Useful conclusions are summarized for engineering designers. Firstly, pitching angles decline along with an increasing nozzle pressure ratio, while systemic thrust ratio and thrust efficiency increase. Secondly, thrust vector angles enlarge with an increase of the injection-to-mainstream momentum flux ratio, whereas both systemic thrust ratio and thrust efficiency decay. Finally, the setup angle of the slot injector impacts the systemic performance remarkably. Although the pitching angle for the setup angle of 120° is highest, comprehensive characteristics in terms of systemic thrust efficiency and systemic thrust ratio for the setup angle of 150° are more excellent.
“…20,21 The above fluidic techniques have some outstanding advantages, for example, fast response, simple mechanical structure, and less thrust loss. 10,11 However, big storage tanks used to store and offer gas or liquid injectant and other assorted equipment increase system weight remarkably. Moreover, once the gas or liquid injectant is not sufficient, the control effectiveness becomes unstable.…”
Mechanical thrust vector control is a classical and important branch in the vectoring control field, offering an extremely reliable control effect. In this article, a simple technology using a cylindrical rod has been numerically investigated to achieve jet controls for three-dimensional conical axisymmetric nozzles. Complex flow phenomena caused by the cylindrical rod on a flat plate and in a converging–diverging nozzle are elucidated with the purpose of a profound understanding of this technique for physical applications. Published experimental data are used to validate the dependability of current CFD results. A grid sensitivity study is carried through and analyzed. The result section discusses the impacts of three factors on performance, involving the rod penetration height, rod location, and nozzle pressure ratio. Significant vectoring performance variations and flow topologies descriptions are illuminated in full detail. When the rod penetration height changes, this technique has an effective control range, namely H/Rt ≤ 0.4. In this effective control range, the vectoring angle and efficiency increase and the thrust coefficient decreases with a deeper rod insertion. As the rod location moves downstream towards the nozzle exit, the vectoring angle increases and the thrust coefficient decays. Moreover, the direction of jet deflection remarkably varies for diverse rod locations. While the nozzle pressure ratio increases, the vectoring angle initially increases to reach the maximum level and then decays slightly. Meanwhile, the thrust coefficient continuously increases.
“…16 performed numerical analyses on steady flow characteristics of the three-dimensional (3-D) conical SVC with a cylindrical injector and reported the influence of NPR and injector position. Furthermore, Wu and Kim 17,18 theoretically and numerically studied the SVC features in a 3-D rectangular SVC with a slot injector and illustrated the effects of momentum flux ratio, slot length-width ratio, and injection angle in detail. Additionally, Deng and Kim 19 and Deng et al.…”
Section: Introductionmentioning
confidence: 99%
“…Although the SVC or B-SVC technique in both conical and rectangular SVC systems can acquire high thrust vectoring angles, induced oblique shocks often diminish the thrust coefficient remarkably. 17–19 Figure 2.Classification of the FTVC.…”
Recently, fluidic thrust vectoring control is popular for micro space launcher propulsion systems due to its several advantages, such as fast dynamic responsiveness, better control effectiveness, and no moving mechanical equipment. Counter-flow thrust vectoring control is an especially effective technique by utilizing less suction flow to control the mainstream deflection flexibly. In the current work, theoretical and numerical analyses are performed together to elaborate on the performance of the three-dimensional rectangular counter-flow thrust vectoring control system. A new propulsion nozzle of Mach 2.5 is devised by method of characteristics. To testify the feasibility and accuracy of the present research methodology, numerical results were validated against experimental data from the open literature. The computational result using the standard k-epsilon turbulence model reveals a good match with experimentally measured static pressure values along the centerline of the upper suction collar. The influence of several key parameters on vectoring performance is investigated herein, including the mainstream temperature, collar radius, horizontal collar length, and gap height. Critical parameters have been quantitatively analyzed, such as static pressure distribution along the centerline of the upper suction collar, pitching angle, suction mass flow ratio, and thrust coefficient. Furthermore, the flow-field features are qualitatively expounded based on the static pressure contour, streamline, iso-turbulent kinetic energy contour, and iso-Mach number contour. Some important conclusions are offered for further studies. The mainstream temperature mainly affects different dynamic characteristics of the mixing shear layer, including the convective Mach number of the shear layer, density ratio, and flow velocity ratio. The collar radius influences the pressure gradient near the suction collar surface significantly. The pitching angle increases rapidly with the increasing collar radius. As the horizontal collar length increases, the systematic deflection angle initially increases then decreases. The highest pitching angle is obtained for L/ H = 3.53. With regard to the gap height, a larger gap height can achieve a higher pitching angle.
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