Увійти

Готові списки джерел за темами / Nozzle-exit conditions

Добірка наукової літератури з теми "Nozzle-exit conditions"

Автор: Grafiati

Опубліковано: 7 липня 2024

Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями

Оберіть тип джерела:

Ознайомтеся зі списками актуальних статей, книг, дисертацій, тез та інших наукових джерел на тему "Nozzle-exit conditions".

Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.

Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.

Зміст

Статті в журналах
Дисертації
Частини книг
Тези доповідей конференцій

Статті в журналах з теми "Nozzle-exit conditions":

1

Kozlov, Viktor, Genrich Grek, Oleg Korobeinichev, Yuriy Litvinenko, and Andrey Shmakov. "Influence Of Initial Conditions At The Micro Nozzle Exit On Hydrogen Diffusion Combustion." Siberian Journal of Physics 11, no. 3 (October 1, 2016): 34–45. http://dx.doi.org/10.54362/1818-7919-2016-11-3-34-45.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

The purpose of the given work will consist in an experimental study of influence of initial conditions at the micro nozzle exit on hydrogen diffusion combustion. It is shown, that the mean velocity profile and presence/absence of a heatcapacious material at the nozzle exit play an essential role on a flame structure and process of a round hydrogen microjet combustion. Velocity ranges of existence of a round hydrogen microjet diffusion combustion, flame separation and «bottleneck flame» region for a case of a top – hat mean velocity profile at the nozzle and two cases of a parabolic mean velocity profile with presence/absence of a heatcapacious material at the nozzle exit are found. Dependences of the «bottleneck flame» region size from a hydrogen microjet efflux velocity for case of a top – hat mean velocity profile at the nozzle and two cases of a parabolic mean velocity profile with presence/absence of a heatcapacious material at the nozzle exit are shown. Decrements of reduction of the «bottleneck flame» region size with growth of the hydrogen microjet efflux velocity for three situations of changes of initial conditions at the nozzle exit are determined.

2

Lepicovsky, J. "An Experimental Investigation of Nozzle-Exit Boundary Layers of Highly Heated Free Jets." Journal of Turbomachinery 114, no. 2 (April 1, 1992): 469–75. http://dx.doi.org/10.1115/1.2929167.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

An experimental investigation of the effects of nozzle operating conditions on the development of nozzle-exit boundary layers of highly heated air free jets is reported in this paper. The total pressure measurements in the nozzle-exit boundary layer were obtained at a range of jet Mach numbers from 0.1 to 0.97 and jet total temperatures up to 900 K. The analysis of results shows that the nozzle-exit laminar boundary-layer development depends only on the nozzle-exit Reynolds number. For the nozzle-exit turbulent boundary layer, however, it appears that the effects of the jet total temperature on the boundary-layer integral characteristics are independent from the effect of the nozzle-exit Reynolds number. This surprising finding has not yet been reported. Further, laminar boundary-layer profiles were compared with the Pohlhausen solution for a flat-wall converging channel and an acceptable agreement was found only for low Reynolds numbers. For turbulent boundary layers, the dependence of the shape factor on relative Mach numbers at a distance of one momentum thickness from the nozzle wall resembles Spence’s prediction. Finally, the calculated total pressure loss coefficient was found to depend on the nozzle-exit Reynolds number for the laminar nozzle-exit boundary layer, while for the turbulent exit boundary layer this coefficient appears to be constant.

3

Fontaine, Ryan A., Gregory S. Elliott, Joanna M. Austin, and Jonathan B. Freund. "Very near-nozzle shear-layer turbulence and jet noise." Journal of Fluid Mechanics 770 (March 27, 2015): 27–51. http://dx.doi.org/10.1017/jfm.2015.119.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

One of the principal challenges in the prediction and design of low-noise nozzles is accounting for the near-nozzle turbulent mixing layers at the high Reynolds numbers of engineering conditions. Even large-eddy simulation is a challenge because the locally largest scales are so small relative to the nozzle diameter. Model-scale experiments likewise typically have relatively thick near-nozzle shear layers, which potentially hampers their applicability to high-Reynolds-number design. To quantify the sensitivity of the far-field sound to nozzle turbulent-shear-layer conditions, a family of diameter $D$ nozzles is studied in which the exit turbulent boundary layer momentum thickness is varied from $0.0042D$ up to $0.021D$ for otherwise identical flow conditions. Measurements include particle image velocimetry (PIV) to within $0.04D$ of the exit plane and far-field acoustic spectra. The influence of the initial turbulent-shear-layer thickness is pronounced, though it is less significant than the well-known sensitivity of the far-field sound to laminar versus turbulent shear-layer exit conditions. For thicker shear layers, the nominally missing region, where the corresponding thinner shear layer would develop, leads to the noise difference. The nozzle-exit momentum thickness successfully scales the high-frequency radiated sound for nozzles of different sizes and exhaust conditions. Yet, despite this success, the detailed turbulence statistics show distinct signatures of the different nozzle boundary layers from the different nozzles. Still, the different nozzle shear-layer thicknesses and shapes have a similar downstream development, which is consistent with a linear stability analysis of the measured velocity profiles.

4

Huh, Kang Y., Eunju Lee, and Jaye Koo. "DIESEL SPRAY ATOMIZATION MODEL CONSIDERING NOZZLE EXIT TURBULENCE CONDITIONS." Atomization and Sprays 8, no. 4 (1998): 453–69. http://dx.doi.org/10.1615/atomizspr.v8.i4.60.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

5

Wang, P. C., and J. J. McGuirk. "Validation of a large eddy simulation methodology for accelerated nozzle flows." Aeronautical Journal 124, no. 1277 (February 18, 2020): 1070–98. http://dx.doi.org/10.1017/aer.2020.12.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

ABSTRACTPrediction of aeroengine exhaust plume near-field development requires knowledge of velocity and turbulence distributions at nozzle exit. The high Reynolds number nozzle inlet boundary layers of engineering practice are fully turbulent, but acceleration can induce re-laminarisation. Thus, to reproduce nozzle exit conditions accurately, large eddy simulation (LES) for plume prediction must be capable of capturing re-laminarisation and any subsequent boundary layer recovery. Validation is essential to establish a credible LES methodology, but previous studies have suffered from lack of nozzle inlet/exit measurements in the test cases selected. Validation data were here taken from an experiment on a convergent round nozzle with a parallel exit extension to allow boundary layer recovery. LES inlet condition generation applied a rescaling/recycling method (R2M), whose performance was validated against measurements of first and second moment statistics as well as the turbulence integral length scale. Simulations employed two sub-grid-scale (SGS) models; these produced similar predictions up to the end of the nozzle convergent section, but marked differences appeared for the nozzle exit turbulence field. The Smagorinsky model predicted much lower turbulence levels than measured, whereas the Piomelli and Geurts model revealed the presence of a small separation region at the convergence/parallel section corner, which led to higher exit turbulence and much better agreement with measured data.

6

Mokni, Amèni, Jamel Kechiche, Hatem Mhiri, Georges Le Palec, and Philippe Bournot. "Numerical Study of the Inlet Conditions Influence on Laminar Plane Wall Jets." Defect and Diffusion Forum 273-276 (February 2008): 406–12. http://dx.doi.org/10.4028/www.scientific.net/ddf.273-276.406.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

In this paper, we present a numerical investigation of a laminar isothermal plane two dimensional wall jets. Special attention has been paid to the effect of the inlet conditions at the nozzle exit on the flow thermal characteristics in forced convection regime. Two velocities profiles at the nozzle exit are used: uniform profile and parabolic profile. The system of equations governing the studied configuration is solved with a finite difference scheme and an implicit scheme, for numerical stability we use a staggered non uniform grid. The obtained results show, first, that the inlet conditions affect the flow in the immediate neighbourhood of the nozzle (core region) in which the flow is governed mainly by the inertias forces. At the established region the results become independent of the flow inlet conditions.

7

Liu, Meng, and Yufeng Duan. "Predicting the Liquid Film Thickness and Droplet–Gas Flow in Effervescent Atomization: Influence of Operating Conditions and Fluid Viscosity." International Journal of Chemical Reactor Engineering 11, no. 1 (September 10, 2013): 393–405. http://dx.doi.org/10.1515/ijcre-2013-0073.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

Abstract The droplet–gas flow in effervescent atomization was simulated using a comprehensive numerical model. Liquid film thicknesses in the nozzle exit orifice and droplet size distribution at the downstream of spray were calculated. The thickness of liquid film in the nozzle exit orifice increased and approached the droplet size in the primary atomization, as the air–liquid ratio increased. The primary breakup model can accurately predict the Sauter mean diameter in the primary atomization when gas–liquid two-phase flow belongs to the annular flow in the nozzle exit orifice. The viscosity of fluid had minimal influence on the liquid film thickness for spray with fluids, the viscosity of which is significantly greater than that of water. Droplet size initially decreased and then increased along the axial distance because of the secondary atomization and droplet coalescence at the downstream of spray.

8

Kim1, H.-D., J.-H. Kim, K.-A. Park, T. Setoguchi, and S. Matsuo. "Study of the effects of unsteady downstream conditions on the gas flow through a critical nozzle." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 218, no. 10 (October 1, 2004): 1163–73. http://dx.doi.org/10.1243/0954406042369053.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

The present study addresses a computational result of unsteady gas flow through a critical nozzle. The axisymmetric unsteady compressible Navier-Stokes equations are solved using a finite volume method that makes use of the second-order upwind scheme for spatial derivatives and the multi-stage Runge-Kutta integral scheme for time derivatives. The steady solutions of the governing equation system are validated with the previous experimental data to ensure that the present computational method is valid to predict the critical nozzle flows. In order to simulate the effects of back-pressure fluctuations on the critical nozzle flows, an excited pressure oscillation with an amplitude and frequency is assumed downstream of the exit of the critical nozzle. The results obtained show that, for low Reynolds numbers, the unsteady effects of the pressure fluctuations can propagate upstream of the throat of the critical nozzle, thus giving rise to the applicable fluctuations in mass flow rate through the critical nozzle, while, for high Reynolds numbers, the pressure signals occurring at the exit of the critical nozzle do not propagate upstream beyond the nozzle throat. For a low Reynolds number, it is found that the sonic line near the throat of the critical nozzle markedly fluctuates with time, providing an important mechanism for pressure signals to propagate upstream of the nozzle throat, even in choked flow conditions. The present study is the first investigation to clarify the unsteady effects on the critical nozzle flows.

9

Menon, Pranav. "Investigation of Variation in the Performance of an Electro Thermal Thruster with Aerospike Nozzle." Advanced Engineering Forum 16 (April 2016): 91–103. http://dx.doi.org/10.4028/www.scientific.net/aef.16.91.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

One of the most recently developed modes of propulsion is electric propulsion. The commonly used chemical propulsion systems have the advantage of a high Specific Impulse as compared to that of ion propulsion systems. However, owing to the efficacy of ion propulsion systems, it is considered the future of space exploration.Electro thermal thrusters produce thrust by using electrical fields to force hot plasma out of the nozzle with certain exit velocity. The plasma’s exit velocity and the system’s thrust capacity, as of now, are insufficient for space travel to be conducted within a reasonable time. I intend to study the possibility of improving the thruster’s performance by using an aerospike nozzle as an exit nozzle which meets the conditions required for the thruster to function appropriately. I shall be studying the plasma plume exit velocity variation with respect to the nozzles used. Also, a thermal analysis will be conducted in order to find the correct material for the nozzle.

10

Mitruka, Jatin, Pranav Kumar Singh, and E. Rathakrishnan. "Exit Geometry Effect on Jet Mixing." Applied Mechanics and Materials 598 (July 2014): 151–55. http://dx.doi.org/10.4028/www.scientific.net/amm.598.151.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

An elliptical nozzle of 3:1 aspect ratio (AR) issuing a Mach 1.5 jet has been used to investigate its mixing promoting efficiency under over-expanded and under-expanded conditions at the nozzle exit. Azimuthal asymmetry of the elliptical shape is interpreted as a benefit to the mixing process, which is significantly enhanced in comparison to an equivalent circular jet under identical conditions. The elliptical jet decays faster than its circular counterpart throughout the jet field. It is found that continuous variation in the size of the mixing promoting vortices shed from the nozzle exit, as a result of its azimuthal asymmetry, is responsible for faster decay of elliptical jet. The visualization of elliptic jet corroborates the fact that the waves prevailing in the elliptical jet are significantly weaker than those in the circular jet.

Більше джерел

Дисертації з теми "Nozzle-exit conditions":

1

Trumper, Miles Thomas. "A study of nozzle exit boundary layers in high-speed jet flows." Thesis, Loughborough University, 2006. https://dspace.lboro.ac.uk/2134/31797.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

The requirement for reduced jet noise in order to meet stringent noise legislation (civil aviation), and low infra-red observability and the use of unconventional exhaust nozzle configurations to improve aircraft survivability and performance (military aviation) is driving research to develop a better understanding of jet development and mixing mechanisms. One option open to the engineer is the use of small-scale model testing to investigate jets flows and provide valuable data for the validation of numerical models. Although more economical than large/full scale testing, additional factors that influence jet development may be present which would not be present at full scale and whose influence needs to be fully understood in order to allow small scale–large scale read-across. One such factor is the nozzle exit boundary layer. Although considerable data exist on the influence of nozzle exit boundary layers on low speed jet flows, current information on high speed jet flows is limited. It was, therefore, the aim of this thesis to extend the current understanding of nozzle exit boundary layers and their influence on the jet development for high speed jet flows through a combination of experimental and computational techniques. A combination of pneumatic probe measurements and Laser Doppler Anemometry (LDA) was used to investigate nozzle inlet and exit boundary layers of simple conical nozzles and the influence of adding a parallel extension piece. The measurements showed that the rapid acceleration of the boundary layer within the nozzle significantly reduced its momentum thickness Reynolds number and changed the state of the boundary layer from turbulent to laminar-like. The addition of a parallel extension to the nozzle exit returned the boundary layer to a fully turbulent state. A low Reynolds number RANS CFD approach was used to investigate the flow within the nozzle. Simulations using the Launder-Sharma low Reynolds number k–ε model revealed that the magnitude of the acceleration within the conical nozzles resulted in the boundary layer beginning to relaminarise. Full relaminarisation was not achieved due to the short axial distance over which the acceleration was sustained. The addition of a parallel extension provided a relaxation region in which the boundary layer could recover from the acceleration to become fully turbulent. Measurements of the jet plume originating from nozzles with laminar-like and turbulent boundary layers showed little influence of the boundary layer shape and thickness on shear layer spreading and jet centreline development.

2

Mayo, David Earl Jr. "The Effect of Combustor Exit to Nozzle Guide Vane Platform Misalignment on Heat Transfer over an Axisymmetric Endwall at Transonic Conditions." Thesis, Virginia Tech, 2016. http://hdl.handle.net/10919/78110.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

This paper presents details of an experimental and computational investigation on the effect of misalignment between the combustor exit and nozzle guide vane endwall on the heat transfer distribution across an axisymmetric converging endwall. The axisymmetric converging endwall investigated was representative of that found on the shroud side of a first stage turbine nozzle section. The experiment was conducted at a nominal exit M of 0.85 and exit Re 1.5 x 10⁶ with an inlet turbulence intensity of 16%. The experiment was conducted in a blowdown transonic linear cascade wind tunnel. Two different inlet configurations were investigated. The first configuration, Case I, was representative of a combustor exit aligned to the nozzle platform, with a gap located at the interface of the tow components. The second configuration, Case II, the endwall platform was offset in the span-wise direction to create a backward facing step at the inlet. This step is representative of a misalignment between the combustor exit and the NGV platform. An infrared camera was used to capture the temperature history on the endwall, from which the endwall heat transfer distribution was determined. A numerical study was also conducted by solving RANS equations using ANSYS Fluent v.15. The numerical results provided insight into the passage flow field which explained the observed heat transfer characteristics. Case I showed the typical characteristics of transonic vane cascade flow, such as the separation line, saddle point, and horseshoe vortices. The presence of a gap at the combustor-nozzle interface facilitated the formation of a separated flow which propagated through the passage. This flow feature caused the passage vortex reattach to the SS vane at 0.44 x/C. The addition of the platform misalignment in Case II caused the flow reattachment region to occur near the vane LE plane. The separated flow which formed at the inlet step, merged with the recirculation region on the endwall platform, forming two counter-rotating auxiliary vortices. These vortices significantly delayed migration of the passage vortex, causing it to reattach on the SS vane at 0.85 x/C. These two flow features also had a significant effect on the endwall heat transfer characteristics. The heat transfer levels on the endwall platform, from -0.50 to +0.50 Cx relative to the vane LE, had an average increase of ~40%. However, downstream of the vane mid-passage, the heat transfer levels showed no appreciable heat transfer augmentation due to flow acceleration through the passage throat.
Master of Science

3

Vincent, Hugo. "Simulations et analyses de sensibilité du bruit produit des écoulements cisaillés." Electronic Thesis or Diss., Ecully, Ecole centrale de Lyon, 2024. http://www.theses.fr/2024ECDL0007.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

Dans ce travail de thèse, des études de sensibilité portant sur le développement et le bruit des écoulements cisaillés turbulents sont réalisées à l'aide de simulations aéroacoustiques directes et de la méthode de la différentiation complexe.Dans un premier temps, la méthode de la différentiation complexe est appliquée à des couches de mélange bidimensionnelles afin d'étudier sa capacité à mettre en évidence les effets d'un paramètre sur les champs aérodynamiques et acoustiques d'un écoulement.Pour cela, des simulations numériques directes de couches de mélange sont réalisées avec cette méthode pour différents nombres de Mach, nombres de Reynolds et tailles de maille.Dans chaque calcul, les dérivées des niveaux acoustiques par rapport à un des trois paramètres considérés sont estimées avec la méthode de la différentiation complexe.Les résultats obtenus sont en bon accord avec d'autres issus de la littérature et d'études paramétriques.Ils indiquent que la méthode de la différentiation complexe peut être utilisée pour, d'une part, étudier l'influence d'un paramètre physique sur le développement et le bruit d'un écoulement et, d'autre part, déterminer la sensibilité au maillage des solutions d'une simulation.Dans un second temps, la méthode de la différentiation complexe est appliquée à l'étude du mécanisme de réceptivité se produisant lorsqu'une onde acoustique se réfléchit sur les lèvres de la buse d'un jet.Dans ce but, à partir des résultats d'une simulation de jet impactant une plaque pleine, un pulse acoustique d'amplitude imaginaire est introduit à un instant donné près de la buse en dehors du jet.En poursuivant la simulation après cet instant, la sensibilité des couches de mélange près de la buse à une perturbation acoustique est déterminée avec la méthode de la différentiation complexe.Cette sensibilité est utilisée pour mettre en évidence la génération d'une onde d'instabilité par la perturbation acoustique.Enfin, l'influence des conditions de sortie de buse (profil de vitesse et taux de turbulence) sur les composantes tonales produites par les jets subsoniques impactant une plaque pleine est étudiée.Pour cela, plusieurs jets impactants sont simulés pour différents profils de vitesse en sortie de buse, plusieurs niveaux d'excitation des couches limites, des nombres de Mach de 0.6 et 0.9, et deux distances plaque-buse.Les résultats montrent que les conditions de sortie affectent considérablement l'amplitude des composantes tonales et que des jets impactants à un nombre de Mach inférieur à 0.65, généralement non résonants, peuvent être résonants pour des conditions de sortie spécifiques.Les effets des conditions de sortie sont attribués à des modifications dans le développement des couches de mélange des jets, qui conduisent à des différences dans les propriétés d'amplification des ondes d'instabilité entre la buse et la plaque, et dans l'énergie contenue dans les structures cohérentes des jets près de la zone d'impact
In this PhD work, sensitivity studies are carried out for turbulent shear flows using direct noise computations and the complex differentiation method.First, the complex differentiation method is applied to two-dimensional mixing layers to investigate its capacity to highlight the effects of a parameter on the aerodynamic noise.For that, direct numerical simulations of mixing layers are performed using this method for different Mach numbers, Reynolds numbers and mesh spacings.In each case, the derivatives of the noise levels with respect to one of the three parameters are obtained using the complex differentiation method.The results are in good agreement with others from the literature and parametric studies.They indicate that the complex differentiation method can be used to describe the effects of physical parameters and of the grid resolution on the sound produced by a high-speed flow.Secondly, the complex differentiation method is applied to the study of the receptivity mechanism occurring when an acoustic wave reflects at the nozzle lip of a jet.For this purpose, using the results of a simulation of a jet impinging on a plate, an imaginary amplitude acoustic pulse is introduced at a given time in the near-nozzle region outside the jet.The sensitivity of the near-nozzle mixing layers to an acoustic disturbance is then determined using the complex differentiation method.This sensitivity is used to highlight the excitation of an instability wave by the acoustic disturbance.Finally, the influence of nozzle-exit conditions (velocity profile and turbulence level) on the tonal noise components generated by subsonic impinging jets is investigated.For that, jets with different nozzle-exit velocity profiles, several boundary-layer excitation levels, at Mach numbers of 0.6 or 0.9, impinging on a plate located at 6 or 8 nozzle radii from the nozzle, are simulated.The results show that the nozzle-exit conditions significantly affect the amplitude of the tonal noise components and that impinging jets at Mach numbers below 0.65, which are generally non-resonant, can be resonant for specific nozzle-exit conditions.The effects of the nozzle-exit conditions are found to result from changes in the development of the jet mixing layers, which lead to differences in the amplification properties of the Kelvin-Helmholtz instability waves between the nozzle and the plate, and in the energy contained in the coherent structures of the jets near the impingement region

Частини книг з теми "Nozzle-exit conditions":

1

Bolgar, Istvan, Sven Scharnowski, and Christian J. Kähler. "Effects of a Launcher’s External Flow on a Dual-Bell Nozzle Flow." In Notes on Numerical Fluid Mechanics and Multidisciplinary Design, 115–27. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-53847-7_7.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

Abstract Previous research on Dual-Bell nozzle flow always neglected the influence of the outer flow on the nozzle flow and its transition from sea level to altitude mode. Therefore, experimental measurements on a Dual-Bell nozzle with trans- and supersonic external flows about a launcher-like forebody were carried out in the Trisonic Wind Tunnel Munich with particle image velocimetry, static pressure measurements and the schlieren technique. A strongly correlated interaction exists between a transonic external flow with the nozzle flow in its sea level mode. At supersonic external flow conditions, a Prandtl–Meyer expansion about the nozzle’s lip decreases the pressure in the vicinity of the nozzle exit by about 55%. Therefore a new definition for the important design criterion of the nozzle pressure ratio was suggested, which considers this drastic pressure drop. Experiments during transitioning of the nozzle from sea level to altitude mode show that an interaction about the nozzle’s lip causes an inherently unstable nozzle state at supersonic free-stream conditions. This instability causes the nozzle to transition and retransition, or flip-flop, between its two modes. This instability can be eliminated by designing a Dual-Bell nozzle to transition during sub-/transonic external flow conditions.

2

Mehta, Rakhab. "Analysis of supersonic free jets and impinging supersonic jets on deflector." In Simulation Modeling - Recent Advances, New Perspectives, and Applications [Working Title]. IntechOpen, 2023. http://dx.doi.org/10.5772/intechopen.1002372.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

The computational fluid dynamics analysis is carried out to analyze the shock and flow characteristics of under- and over expanded supersonic free jets emanating from convergent-divergent nozzles. Influence of exit Mach number on shock cell lengths are analyzed with the help of density contours and schlieren images. A parameter based on an exit Mach number is obtained to characterize the pressure variation along the jet axis which shows them independent of the exit to ambient pressure ratio. Impingement flow fields over axisymmetric and wedge deflector are investigated employing numerically and compared with experimental results. Effects of jet expansion ratio and distance between the nozzle to deflector apex has been studied at various expansion ratios and distances. Impingement load is computed at various conditions. Pressure distributions over a surface of wedge and axisymmetric jet deflector are computed and compared between them. Pressure load on a diaphragm of a solid motor during lift-off of a satellite launch vehicle having four liquid engines is numerically simulated.

Тези доповідей конференцій з теми "Nozzle-exit conditions":

1

Zaman, Khairul. "Effect of nozzle exit conditions on subsonic jet noise." In 17th AIAA/CEAS Aeroacoustics Conference (32nd AIAA Aeroacoustics Conference). Reston, Virigina: American Institute of Aeronautics and Astronautics, 2011. http://dx.doi.org/10.2514/6.2011-2704.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

2

Panda, J., K. Zaman, and R. Seasholtz. "Measurements of initial conditions at nozzle exit of high-speed jets." In 7th AIAA/CEAS Aeroacoustics Conference and Exhibit. Reston, Virigina: American Institute of Aeronautics and Astronautics, 2001. http://dx.doi.org/10.2514/6.2001-2143.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

3

Barre, Sebastien, Christophe Bogey, and Christophe Bailly. "Computation of the Noise Radiated by Jets with Laminar/Turbulent Nozzle-Exit Conditions." In 12th AIAA/CEAS Aeroacoustics Conference (27th AIAA Aeroacoustics Conference). Reston, Virigina: American Institute of Aeronautics and Astronautics, 2006. http://dx.doi.org/10.2514/6.2006-2443.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

4

LEPICOVSKY, J., and W. BROWN. "Effects of nozzle-exit boundary-layer conditions on excitability of heated free jets." In 11th Aeroacoustics Conference. Reston, Virigina: American Institute of Aeronautics and Astronautics, 1987. http://dx.doi.org/10.2514/6.1987-2723.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

5

Bolot, R., D. Klein, and C. Coddet. "Design of a Nozzle Extension for Thermal Spray Under Very Low Pressure Conditions." In ITSC2004, edited by Basil R. Marple and Christian Moreau. ASM International, 2004. http://dx.doi.org/10.31399/asm.cp.itsc2004p0574.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

Abstract Conventional equipments used for low pressure plasma spraying are designed for a chamber pressure of a few tens of mbar. During the past three years, an increasing interest for thermal spray under very low pressure conditions (as low as 1 mbar) was encountered but no significant advances concerning the spray gun design was proposed. However, it is clear that actual tools do not allow providing uniform plasma jets and that the produced jets present successive expansions and constrictions due to a poor adaptation of the nozzle exit pressure regarding to the chamber one. In the present paper, the use of a nozzle extension is proposed. The holding nozzle is a lengthened F4 type one and the diverging part of the nozzle is formed by a fastened external extension. The design of the nozzle extension is a bell-contoured Laval type one and its dimensions (exit diameter and length) are much higher than for conventional diverging nozzles. An improvement in the jet homogeneity and uniformity is expected.

6

Zhang, Kun, Bo Zhang, Xu Xiang, and Yong Yang. "Numerical Comparison of Operating Conditions and Nozzle Geometry on Injector Performance." In ASME 2013 Heat Transfer Summer Conference collocated with the ASME 2013 7th International Conference on Energy Sustainability and the ASME 2013 11th International Conference on Fuel Cell Science, Engineering and Technology. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/ht2013-17207.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

A model was established to discuss the effect of operating parameters and nozzle shapes on the performance of injectors. The comparison pointed out that heat load has worst effect on injector geometries, while little effect on area ratio. On the other hand, the area ratio is very sensitive to suction temperature, which is critical to injector performance. The least energy loss is achieved when nozzle converges gently at the same nozzle entrance and exit diameter.

7

Bishop, Kristen, and William Allan. "Effects of Fuel Nozzle Condition on Gas Turbine Combustion Chamber Exit Temperature Distributions." In ASME Turbo Expo 2010: Power for Land, Sea, and Air. ASMEDC, 2010. http://dx.doi.org/10.1115/gt2010-23441.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

The effects of fuel nozzle condition on the temperature distributions experienced by the nozzle guide vanes have been investigated using an optical patternator. Average spray cone angle, symmetry, and fuel streaks were quantified. An ambient pressure and temperature combustion chamber test rig was used to capture exit temperature distributions and to determine the pattern factor. The rig tests matched representative engine operating conditions by matching Mach number, equivalence ratio, and fuel droplet size. It was observed that very small deviations (± 10° in spray cone angle) from a nominal distribution in the fuel nozzle spray pattern correlated to increases in pattern factor, apparently due to a degradation of mixing processes, which created larger regions of very high temperature core flow and smaller regions of cooler temperatures within the combustion chamber exit plane. The spray cone angle had the most measureable influence while the effects of spray roundness and streak intensity had slightly less influence. Comparisons were made with published studies conducted on the combustion chamber geometry, and recommendations were made for fuel nozzle inspections.

8

Lepicovsky, J. "An Experimental Investigation of Nozzle-Exit Boundary Layers of Highly Heated Free Jets." In ASME 1990 International Gas Turbine and Aeroengine Congress and Exposition. American Society of Mechanical Engineers, 1990. http://dx.doi.org/10.1115/90-gt-255.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Анотація:

An experimental investigation of the effects of nozzle operating conditions on the development of nozzle-exit boundary layers of highly heated air free jets is reported in this paper. The total pressure measurements in the nozzle-exit boundary layer were obtained at a range of jet Mach numbers from 0.1 to 0.97 and jet total temperatures up to 900 K. The analysis of results shows that the nozzle-exit laminar boundary-layer development depends only on the nozzle-exit Reynolds number. For the nozzle-exit turbulent boundary layer, however, it appears that the effects of the jet total temperature on the boundary-layer integral characteristics are independent from the effect of the nozzle-exit Reynolds number. This surprizing finding has not yet been reported. Further, laminar boundary-layer profiles were compared with the Pohlhausen solution for a flat-wall converging channel and an acceptable agreement was found only for low Reynolds numbers. For turbulent boundary layers, the dependence of the shape factor on relative Mach numbers at a distance of one momentum thickness from the nozzle wall resembles Spence’s prediction. Finally, the calculated total pressure loss coefficient was found to depend on the nozzle-exit Reynolds number for the laminar nozzle-exit boundary layer, while for the turbulent exit boundary layer this coefficient appears to be constant.

9

Litvinenko, Yu A., G. R. Grek, G. V. Kozlov, A. M. Sorokin, and M. V. Litvinenko. "Development of a free round jet at different conditions at the nozzle exit under an acoustic action." In Progress in Flight Physics. Les Ulis, France: EDP Sciences, 2012. http://dx.doi.org/10.1051/eucass/201203429.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

10

Liu, Junhui, K. Kailasanath, Jay Boris, Nick Heeb, David Munday, and Ephraim Gutmark. "Effect of Nozzle-exit Flow Conditions on the Flow and Acoustic Properties of Imperfectly Expanded Supersonic Jets." In 18th AIAA/CEAS Aeroacoustics Conference (33rd AIAA Aeroacoustics Conference). Reston, Virigina: American Institute of Aeronautics and Astronautics, 2012. http://dx.doi.org/10.2514/6.2012-2161.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.