A Description of the Pressure Swirl Atomizer Internal Flow

Donjat, David; Estivalèzes, Jean-Luc; Michau, M.

doi:10.1115/fedsm2002-31017

Cited by 12 publications

(15 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The higher peak appears to be the result of the rotating double helix wave. These results concur with those of Donjat et al [18] who also found two fundamental spectral frequencies and also mention the presence of capillary waves, in addition to the helical and air core precession, based on numerical results and laser spectrum analysis. Figure 6 indicates that the highest magnitudes of the velocity components are found near the air core, with the second highest values in the near wall region.…”

Section: Small Amplitude Capillary Wavessupporting

confidence: 92%

Stationary rotary force waves on the liquid–air core interface of a swirl atomizer

Chinn

Cooper

Yule³

et al. 2015

Heat Mass Transfer

View full text Add to dashboard Cite

Section: Small Amplitude Capillary Wavessupporting

confidence: 92%

Stationary rotary force waves on the liquid–air core interface of a swirl atomizer

Chinn

Cooper

Yule³

et al. 2015

Heat Mass Transfer

View full text Add to dashboard Cite

“…Experimentally, such helical structure has been observed by several authors, including Kim et al (2009), Donjat et al (2002) and Cooper and Yule (2001), while the phenomenon has also been demonstrated in CFD simulations by Dash et al (2001). The variation of the air core may induce large fluctuations of the film thickness and affect the subsequent atomization process (Amini, 2016).…”

Section: Introductionmentioning

confidence: 77%

Analysis of viscous fluid flow in a pressure-swirl atomizer using large-eddy simulation

Laurila

Roenby

Maakala

et al. 2019

International Journal of Multiphase Flow

View full text Add to dashboard Cite

A computational fluid dynamics study is carried out on the inner nozzle flow and onset of liquid sheet instability in a large-scale pressure-swirl atomizer with asymmetric inflow configuration for high viscosity fluids. Large-eddy simulations (LES) of the two-phase flow indicate the unsteady flow character inside the nozzle and its influence on liquid sheet formation. A novel geometric volume-offluid (VOF) method by Roenby et al., termed isoAdvector, is applied for sharp interface capturing (Roenby J., Bredmose H., Jasak H., 2016, A computational method for sharp interface advection, Royal Society Open Science 3). We carry out a Reynolds number sweep (420 ≤ Re ≤ 5300) in order to investigate the link between the asymmetric inner nozzle flow and liquid sheet characteristics in laminar, transitional and fully turbulent conditions. Inside the nozzle, the numerical simulations reveal counter-rotating Dean vortices, flow impingement locations, and strong asymmetric flow features at all investigated Reynolds numbers. A helical, rotating gaseous core is observed when Re ≥ 1660. For laminar flow (Re = 420), an S-shaped liquid film is observed, while the gas core presence at Re ≥ 1660 results in a hollow cone liquid sheet. For the intermediate value Re = 830, the numerical simulations indicate a liquid sheet of mixed type.

show abstract

“…These features of the flow are clearly amenable to a boundary layer type of analysis. However, recirculation in the bulk of the atomizer chamber, which is a prominent feature displayed by experimental visualizations (Binnie et al 1957;Wang et al 1999;Donjat et al 2003) and numerical computations (Jeng et al 1998;Yule & Chinn 2000;Nouri-Borujerdi & Kebriaee 2012) for moderate to small values of the atomizer constant, can hardly be accounted for using a boundary layer approximation. The size of the recirculation region and the direction of circulation of the liquid depend on the inlet conditions.…”

Section: Viscous Effectsmentioning

confidence: 99%

“…Experiments with various geometrical configurations, liquid properties and injection pressures and/or flow rates (Dombrowski & Hasson 1969;Rizk & Lefebvre 1985;Horvay & Leuckel 1986;Suyari & Lefebvre 1986;Kim et al 2009) have clarified the effects of these parameters on the characteristics of the atomizer, allowing one to assess and to extend the predictions of irrotational theories (Lefebvre 1989). Large-scale models made of transparent materials have allowed optical access and measurements at increased spatial resolution with laser Doppler velocimetry, particle image velocimetry, laser-induced fluorescence and high-speed video techniques (Horvay & Leuckel 1986;Holtzclaw et al 1997;Wang et al 1999;Donjat et al 2003). These experiments have revealed the complexity of the flow in the chamber, which includes regions of very different axial and azimuthal velocities, recirculation, non-steadiness, lack of axisymmetry and waves propagating on the liquid-air interface.…”

Section: Introductionmentioning

confidence: 99%

Quasi-cylindrical approximation to the swirling flow in an atomizer chamber

Higuera

Pereña

2014

J. Fluid Mech.

View full text Add to dashboard Cite

A quasi-cylindrical approximation is used to analyse the axisymmetric swirling flow of a liquid with a hollow air core in the chamber of a pressure swirl atomizer. The liquid is injected into the chamber with an azimuthal velocity component through a number of slots at the periphery of one end of the chamber, and flows out as an annular sheet through a central orifice at the other end, following a conical convergence of the chamber wall. An effective inlet condition is used to model the effects of the slots and the boundary layer that develops at the nearby endwall of the chamber. An analysis is presented of the structure of the liquid sheet at the end of the exit orifice, where the flow becomes critical in the sense that upstream propagation of long-wave perturbations ceases to be possible. This analysis leads to a boundary condition at the end of the orifice that is an extension of the condition of maximum flux used with irrotational models of the flow. As is well known, the radial pressure gradient induced by the swirling flow in the bulk of the chamber causes the overpressure that drives the liquid towards the exit orifice, and also leads to Ekman pumping in the boundary layers of reduced azimuthal velocity at the convergent wall of the chamber and at the wall opposite to the exit orifice. The numerical results confirm the important role played by the boundary layers. They make the thickness of the liquid sheet at the end of the orifice larger than predicted by irrotational models, and at the same time tend to decrease the overpressure required to pass a given flow rate through the chamber, because the large axial velocity in the boundary layers takes care of part of the flow rate. The thickness of the boundary layers increases when the atomizer constant (the inverse of a swirl number, proportional to the flow rate scaled with the radius of the exit orifice and the circulation around the air core) decreases. A minimum value of this parameter is found below which the layer of reduced azimuthal velocity around the air core prevents the pressure from increasing and steadily driving the flow through the exit orifice. The effects of other parameters not accounted for by irrotational models are also analysed in terms of their influence on the boundary layers.

show abstract

A Description of the Pressure Swirl Atomizer Internal Flow

Cited by 12 publications

References 0 publications

Stationary rotary force waves on the liquid–air core interface of a swirl atomizer

Stationary rotary force waves on the liquid–air core interface of a swirl atomizer

Analysis of viscous fluid flow in a pressure-swirl atomizer using large-eddy simulation

Quasi-cylindrical approximation to the swirling flow in an atomizer chamber

Contact Info

Product

Resources

About