Effects of Injection Angle on Atomization of Liquid Jets in Transverse Airflow

Fuller, Raymond P.; Wu, Pei-Kuan; Kirkendall, Kevin A.; Nejad, A. S.

doi:10.2514/2.923

Cited by 47 publications

(20 citation statements)

References 23 publications

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“…It was observed that wall static pressure upstream of the injection point increases with increase in the momentum flux ratios. Fuller et al (2000) conducted experimental investigations for the effect of injection angles on the atomization of the liquid jets in transverse air flow. Boles et al (2010) conducted computational investigations using LES and RANS simulations of sonic injection into a Mach 2 cross stream of air, helium, and ethylene to predict the upstream boundary layer structure.…”

Section: Review Of Literaturementioning

confidence: 99%

Numerical Studies on Thrust Augmentation in High Area Ratio Rocket Nozzles by Secondary Injection

Shyji¹,

Deepu

Kumar³

et al. 2017

JAFM

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Single stage to orbit propulsion devices are being developed as part of low cost access to space endeavors. Sea level operation of high area ratio rocket nozzle used in rocket engines leads to an overexpanded flow condition resulting in high side loads. Secondary injection of propellants in high area ratio nozzle is an attractive option to overcome the inefficiency of operation of such nozzles in sea level conditions in addition to the augmentation of thrust. A numerical study on thrust augmentation in high area ratio nozzle by secondary injection of propellants is presented here. The turbulent compressible reacting flow in rocket nozzle with auxiliary injection is simulated using conservation equations for chemical species based on finite rate chemistry model and compressible Navier-Stokes equations with AUSM+-up upwind scheme based unstuctured finite volume solver. An optimized eight step, six species reduced H2-O2finite chemistry reaction model is used to model the supersonic combustion. The indigenously developed solver has an efficient rescaling algorithm to alleviate the effect of stiffness in conventional explicit algorithm for simultaneous solution of reacting flow. The code is validated using the wall pressure and hydrogen concentration values reported for the similar high area ratio rocket nozzle. Accurate prediction of nozzle performance is possible with present turbulent reacting flow simulation as it take care of all losses in nozzle flow. Extensive computations have been performed for the performance estimation of high area ratio rocket nozzle for various prospective auxiliary injection options.

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Section: Review Of Literaturementioning

confidence: 99%

Numerical Studies on Thrust Augmentation in High Area Ratio Rocket Nozzles by Secondary Injection

Shyji¹,

Deepu

Kumar³

et al. 2017

JAFM

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“…For a long time, the liquid jet that is injected perpendicularly into subsonic crossflows and atomized into fine drops by aerodynamic forces has been studied for application in liquid-fueled combustors, such as ramjet engines, scramjet engines, and the afterburner of jet engines. Since the combustion efficiency of these combustors is significantly influenced by the breakup characteristics of the liquid jet, considerable research has been carried out experimentally and analytically on the breakup characteristics of the liquid jet (Schetz et al (1977), Nguyen et al (1992), Inamura (2000), Wu et al (1997), Fuller et al (2000), Schetz et al (1980), Ingebo (1984), Inamura et al (1999)). Generally, the liquid jet (liquid column), breaks up into liquid clumps (ligaments), and a liquid clump disintegrates into finer particles (droplets).…”

Section: Introductionmentioning

confidence: 99%

“…They confirmed these assumptions through experiments and proposed an empirical correlation of the liquid column trajectories consisting of an injector diameter and liquid/air momentum flux ratio. Fuller et al (2000) investigated the effects of injection angle on the column trajectories in transverse airflows. Schetz et al (1980) indicated that the growth of the acceleration wave on the liquid column by aerodynamic force was an important factor of the breakup process.…”

Section: Introductionmentioning

confidence: 99%

Experimental Study of Cavitation and Hydraulic Flip Effects on Liquid Jet Characteristics into Crossflows

2012

JAFM

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In this work, the effects of orifice internal flow, such as cavitation and hydraulic flip, on the breakup processes of the liquid jet injected perpendicularly into subsonic crossflows were studied experimentally. To provide several conditions for orifice internal flow, different orifice diameters, injection pressure differentials, and shapes (sharp and round) of the orifice entrance were used. Photographs of liquid flow inside the orifice confirmed the internal flow condition. A stroboscopic light was used to measure the liquid column breakup lengths and the liquid column trajectories. The results showed that the liquid column trajectories in noncavitation flows and cavitation flows had a similar trend, but the liquid column trajectories in hydraulic flip flows had different results because the surface of the liquid in the hydraulic flip flows was detached from the inner wall of the orifice hole. As cavitation bubbles developed inside the sharp-edged orifice, the liquid jet became more turbulent and unsteady. Therefore, the liquid column breakup lengths in the cavitation flows were shorter than those in noncavitation flows. In the hydraulic flip, the breakup lengths had smaller values because the liquid jet diameter was smaller than the orifice diameter, and the acceleration waves occurring on the liquid column spread upstream of the orifice exit, then the breakup process on the liquid jet started from the orifice entrance.

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“…Debido al alto consumo de combustible se observa una gran producción tanto de especies finales como precursoras del hollín. El hollín, componente principal del material particulado generado en el proceso de combustión Diesel [57], comienza a formarse cerca del máximo característico de la ley de liberación de calor, inicialmente como partículas muy pequeñas en la zona frontal del chorro hasta consolidarse en los límites de la llama de difusión. La radiación del hollín producida por la incandescencia de las partículas, presentaórdenes de magnitud muy por encima de la emisión quimioluminiscente y son estas partículas las que ocupan la sección principal del chorro.…”

Section: Atomizaciónunclassified

“…Estos resultados sirvieron a la ampliación y validación del modelo de chorro Diesel presentado un año antes por uno de los autores [38]. Otros trabajos donde se visualiza la molécula NO con las técnicas de LIF se encuentra en [57,58].…”

Section: Técnicas Lif Para Estudios De Combustiónunclassified

Caracterización de los procesos de Inyección-Combustión Diesel mediante visualización y procesado digital de imágenes

Pemberthy¹,

Daniel²

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Valencia, Abril de 2010 ResumenEl objetivo de esta tesis doctoral ha sido el desarrollo de metodologías completas para la caracterización experimental de los procesos de inyección de combustible, evaporación y formación de mezcla, autoencendido y combustión en toberas reales de múltiples orificios de motores Diesel. Para el logro del objetivo se han implementado diferentes técnicas de visualización y se han desarrollado los algoritmos para el procesado automático de las imágenes.El estudio de visualización del chorro líquido, en instalaciones experimentales de uno o más accesosópticos amplios, se ha centrado en el análisis del efecto de la configuración opto-electrónica sobre la calidad de las imágenes, y se han diseñado y evaluado nuevos algoritmos de procesado. Como aportación innovadora se ha generalizado el algoritmo de segmentación LRT para el caso de distribuciones no normales. Para el estudio de la evaporación de chorros, reactivos o inertes, se implementaron las técnicas de Schlieren y Shadowgraph en dos variantes básicas según la disponibilidad de accesos: método de transmisión y método de doble paso. Se realizó un estudio teórico-experimental completo, con la finalidad de precisar las variables que afectan la sensibilidad e identificar las principales fuentes de error en el análisis de las imágenes. Los algoritmos propuestos toman como base los de segmentación de chorro líquido con pequeñas modificaciones en el cálculo del nivel digital umbral.El estudio del autoencendido y combustión se llevó a cabo mediante el registro de la emisión natural de quimioluminiscencia de los radicales CH y OH y de la radiación térmica del hollín. Se analiza en detalle la sensibilidad del método de visualización a la configuración del instrumental de adquisición y se plantea una metodología de análisis de imágenes basada en el estudio estadístico de las distribuciones espaciales de intensidad. AbstractThe objective of this doctoral thesis has been the development of complete methodologies for the experimental characterization of the processes of fuel injection, vaporization and mixture formation, autoignition and combustion in real multi-orifice nozzles for Diesel engines. Different visualization techniques have been implemented to achieve this objective, and algorithms for automatic image processing have been developed.The study of liquid spray visualization, in experimental facilities with one or more wide optical accesses, has focused on the analysis of the effect of the opto-electronic configuration upon the image quality, and new processing algorithms have been designed and evaluated. As an innovative contribution, the LRT segmentation algorithm has been generalized to non-Gaussian distributions.Schlieren and Shadowgraph techniques have been implemented for the study of vaporizing sprays making use of two basic variants, according to the availability of optical accesses: transmission method and double-pass method. A complete theoretical-experimental study has been carried out, with the aim of defining the variables th...

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Effects of Injection Angle on Atomization of Liquid Jets in Transverse Airflow

Cited by 47 publications

References 23 publications

Numerical Studies on Thrust Augmentation in High Area Ratio Rocket Nozzles by Secondary Injection

Numerical Studies on Thrust Augmentation in High Area Ratio Rocket Nozzles by Secondary Injection

Experimental Study of Cavitation and Hydraulic Flip Effects on Liquid Jet Characteristics into Crossflows

Caracterización de los procesos de Inyección-Combustión Diesel mediante visualización y procesado digital de imágenes

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