Breakup Processes of Liquid Jets in Subsonic Crossflows

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

doi:10.2514/2.5151

Cited by 356 publications

(97 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Pai et al [3] identify four adimensional numbers for the jet behavior and atomization : the jet-to-crossflow momentum flux ratio q, the aerodynamic Weber number W eg, the liquid Reynolds number Re l and the Ohnesorge number Oh l . Wu et al [4] studied experimentally the influence of these parameters on the behavior of the jet. They observed similarities [5] between liquid jet primary breakup regimes and those reported by Hsiang and Faeth [6] for secondary breakup of droplets.…”

Section: Introductionmentioning

confidence: 99%

Multi-scale Eulerian-Lagrangian simulation of a liquid jet in cross-flow under acoustic perturbations

Thuillet¹,

Zuzio²,

Rouzaud³

et al. 2017

Proceedings ILASS–Europe 2017. 28th Conference on Liquid Atomization and Spray Systems

View full text Add to dashboard Cite

The design of modern aeronautical propulsion systems is constantly optimized to reduce pollutant emissions while increasing fuel combustion efficiency. In order to get a proper mixing of fuel and air, Liquid Jets Injected in gaseous Crossflows (LJICF) are found in numerous injection devices. However, should combustion instabilities appear in the combustion chamber, the response of the liquid jet and its primary atomization is still largely unknown. Coupling between an unstable combustion and the fuel injection process has not been well understood and can result from multiple basic interactions. The aim of this work is to predict by numerical simulation the effect of an acoustic perturbation of the shearing air flow on the primary breakup of a liquid jet. Being the DNS approach too expensive for the simulation of complex injector geometries, this paper proposes a numerical simulation of a LJICF based on a multiscale approach which can be easily integrated in industrial LES of combustion chambers. This approach results in coupling of two models: a two-fluid model, based on the Navier-Stokes equations for compressible fluids, able to capture the largest scales of the jet atomization and the breakup process of the liquid column; and a dispersed phase approach, used for describing the cloud of droplets created by the atomization of the liquid jet. The coupling of these two approaches is provided by an atomization and re-impact models, which ensure liquid transfer between the two-fluid model and the spray model. The resulting numerical method is meant to capture the main jet body characteristics, the generation of the liquid spray and the formation of a liquid film whenever the spray impacts a solid wall. Three main features of the LJICF can be used to describe, in a steady state flow as well as under the effect of the acoustic perturbation, the jet atomization behavior: the jet trajectory, the jet breakup length and droplets size and distribution. The steady state simulations provide good agreement with ONERA experiments conducted under the same conditions, characterized by a high Weber number (We>150). The multiscale computation gives the good trajectory of the liquid column and a good estimation of the column breakup location, for different liquid to air momentum flux ratios. The analysis of the droplet distribution in space is currently undergoing. A preliminary unsteady simulation was able to capture the oscillation of the jet trajectory, and the unsteady droplets generation responding to the acoustic perturbation. Keywords multiscale numerical simulation, liquid jet in gaseous crossflow, acoustic perturbation, Euler-Lagrange coupling IntroductionThe liquid jet in crossflow (LJICF) configuration covers several applications in engineering systems, such as combustion, chemical or even agriculture fields. Particularly in aircraft combustion chambers, systems where the fuel jet is injected normally into an air crossflow are commonly used. Compared with a free jet into a quiescent flow, this configuration enab...

show abstract

Section: Introductionmentioning

confidence: 99%

Multi-scale Eulerian-Lagrangian simulation of a liquid jet in cross-flow under acoustic perturbations

Thuillet¹,

Zuzio²,

Rouzaud³

et al. 2017

Proceedings ILASS–Europe 2017. 28th Conference on Liquid Atomization and Spray Systems

View full text Add to dashboard Cite

show abstract

“…Higher Weber number and lower length to diameter of the nozzle (l/d) were used in [3], where as lower Weber numbers and higher length to diameter ratio of the nozzle were used in [7]. Studies [3] and [6] gave a single equation for a wide range of momentum flux ratio. Liquid was injected at an angle of 15°, 30° and 45° with the air flow direction in [5].…”

Section: Introductionmentioning

confidence: 99%

“…Table 1 shows the correlations for breakup length from different studies. In studies [3] to [7], correlations were developed for breakup length in terms of the momentum flux ratio. In addition to the momentum flux ratio, Ohnesorge number was included when liquid viscosity exceeds 0.019 Pa.s in [4].…”

Section: Introductionmentioning

confidence: 99%

“…Experiments were conducted in different air flow conditions: normal temperature and pressure in [3] to [7], elevated pressure (10 bar) in [8], and elevated temperature (327 °C) and pressure (10-20 bar) in [9]. Higher Weber number and lower length to diameter of the nozzle (l/d) were used in [3], where as lower Weber numbers and higher length to diameter ratio of the nozzle were used in [7]. Studies [3] and [6] gave a single equation for a wide range of momentum flux ratio.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Break up length on Urea Water Solution jet in hot cross flow

Senthilkumar

Bakshi

Anand

2017

Proceedings ILASS–Europe 2017. 28th Conference on Liquid Atomization and Spray Systems

View full text Add to dashboard Cite

Selective Catalytic Reduction (SCR) using Urea-Water Solution (UWS) as an ammonia precursor is considered as one of the best choices to meet the current stringent emission norms for reduction of NOX in diesel engines. UWS sprayed in the engine exhaust line forms ammonia, and this ammonia reduces NOX into nitrogen. The NOX reduction efficiency depends on the mixing and evaporation behavior of the UWS spray in the hot exhaust gas. Spray characteristics decide the evaporation rate and hence the NOX reduction efficiency. The spray structure is closely related to the breakup point and breakup mode of the jet. Hence, in this study, breakup length and breakup mode were investigated by injecting UWS (32.5 % by weight) through a nozzle in a hot air cross flow. A CCD camera and pulsed Nd:Yag laser were used for capturing the images. Experiments were conducted with varying nozzle size (150, 250 and 400 micron), injection pressure (0.5 to 3 bar), temperature (32 °C,150 °C and 200 °C) and air flow rate. The effect of operating parameters (nozzle size, injection pressure, air temperature and velocity) in terms of dimensionless numbers (Weber number and momentum flux ratio) on jet breakup mode and jet breakup length was studied. It was observed that the breakup length for UWS was close to that of water. The jet breakup length increases with momentum flux ratio since a jet having a higher momentum is able to penetrate a larger distance in the cross flow. Increasing the air temperature increases the velocity of the cross flow and hence reduces the breakup length. A correlation for jet breakup length was developed. The effect of inclusion of Weber number in the breakup length correlation, in addition to the momentum flux ratio, was studied. Visual observation shows that droplet sizes obtained from the plain orifice injector without preheating is large. Preheating the UWS before injection is recommended to reduce the droplet size. Keywords UWS, cross flow, breakup length and laser diagnostics. IntroductionDiesel engines deliver a high thermal efficiency, high torque density and good fuel economy. However, emissions produced by diesel engines, especially oxides of nitrogen (NOx), pose a major problem to the environment and to human health. In-cylinder treatment methods like retarding injection timing, Exhaust Gas Recirculation (EGR) and exhaust after treatment methods like three-way catalysts and lean NOX traps are not suitable to meet future US and European emission norms. Urea-SCR after treatment method has the ability to meet these norms [1].

show abstract

“…Most of the past studies were focused on jet path and depth of penetration and jet lateral spread [11]. Woo et al [2] used a force balance in cross air direction between aero dynamical acceleration Force and after force on jet pillar to simulate jet movement path.…”

Section: Introductionmentioning

confidence: 99%

Numerical Investigation on Transversely Liquid Jet in Air Flow

2017

International Journal of Modern Studies in Mechanical Engineeri

View full text Add to dashboard Cite

Breakup Processes of Liquid Jets in Subsonic Crossflows

Cited by 356 publications

References 21 publications

Multi-scale Eulerian-Lagrangian simulation of a liquid jet in cross-flow under acoustic perturbations

Multi-scale Eulerian-Lagrangian simulation of a liquid jet in cross-flow under acoustic perturbations

Break up length on Urea Water Solution jet in hot cross flow

Numerical Investigation on Transversely Liquid Jet in Air Flow

Contact Info

Product

Resources

About