Linear instability of an annular liquid jet with gas velocity oscillations

2021 ◽  
Vol 33 (5) ◽  
pp. 054110
Author(s):  
Xin-yan Guan ◽  
Bo-qi Jia ◽  
Li-jun Yang ◽  
Qing-fei Fu
Keyword(s):  
Linear Instability ◽  
Liquid Jet ◽  
Gas Velocity ◽  
Annular Liquid Jet

Linear Instability Analysis of an Annular Swirling Viscous Liquid Jet

2011 ◽  
Vol 66-68 ◽  
pp. 1556-1561 ◽  
Author(s):  
Kai Yan ◽  
Ming Lv ◽  
Zhi Ning ◽  
Yun Chao Song
Keyword(s):  
Viscous Liquid ◽  
Liquid Velocity ◽  
Aerodynamic Force ◽  
Numerical Procedure ◽  
Liquid Sheet ◽  
Linear Instability ◽  
Viscous Force ◽  
Liquid Jet ◽  
Instability Analysis ◽  
Linear Instability Analysis

A three-dimensional linear instability analysis was carried out for an annular swirling viscous liquid jet with solid vortex swirl velocity profile. An analytical form of dispersion relation was derived and then solved by a direct numerical procedure. A parametric study was performed to explore the instability mechanisms that affect the maximum spatial growth rate. It is observed that the liquid swirl enhances the breakup of liquid sheet. The surface tension stabilizes the jet in the low velocity regime. The aerodynamic force intensifies the developing of disturbance and makes the jet unstable. Liquid viscous force holds back the growing of disturbance and the makes the jet stable, especially in high liquid velocity regime.

scholarly journals Effects of Asymmetric Gas Distribution on the Instability of a Plane Power-Law Liquid Jet

Energies ◽  
2018 ◽  
Vol 11 (7) ◽  
pp. 1854 ◽  
Author(s):  
Jin-Peng Guo ◽  
Yi-Bo Wang ◽  
Fu-Qiang Bai ◽  
Fan Zhang ◽  
Qing Du
Keyword(s):  
Power Law ◽  
Liquid Velocity ◽  
Linear Instability ◽  
Liquid Jets ◽  
Liquid Jet ◽  
Critical Curves ◽  
Jet Breakup ◽  
Plane Jets ◽  
Gas Space ◽  
Aerodynamic Asymmetry

As a kind of non-Newtonian fluid with special rheological features, the study of the breakup of power-law liquid jets has drawn more interest due to its extensive engineering applications. This paper investigated the effect of gas media confinement and asymmetry on the instability of power-law plane jets by linear instability analysis. The gas asymmetric conditions mainly result from unequal gas media thickness and aerodynamic forces on both sides of a liquid jet. The results show a limited gas space will strengthen the interaction between gas and liquid and destabilize the power-law liquid jet. Power-law fluid is easier to disintegrate into droplets in asymmetric gas medium than that in the symmetric case. The aerodynamic asymmetry destabilizes para-sinuous mode, whereas stabilizes para-varicose mode. For a large Weber number, the aerodynamic asymmetry plays a more significant role on jet instability compared with boundary asymmetry. The para-sinuous mode is always responsible for the jet breakup in the asymmetric gas media. With a larger gas density or higher liquid velocity, the aerodynamic asymmetry could dramatically promote liquid disintegration. Finally, the influence of two asymmetry distributions on the unstable range was analyzed and the critical curves were obtained to distinguish unstable regimes and stable regimes.

Simulation of an annular liquid jet with a coaxial supersonic gas jet in a medical inhaler

2021 ◽  
Author(s):  
Yanchao Liu ◽  
Anne Geppert ◽  
Chu Xu ◽  
Benjamin Heine ◽  
Bernhard Weigand
Keyword(s):  
Gas Jet ◽  
Liquid Jet ◽  
Supersonic Gas Jet ◽  
Annular Liquid Jet

Curved Non-Newtonian Liquid Jets With Surfactants

2009 ◽  
Vol 131 (9) ◽  
Author(s):  
Jamal Uddin ◽  
Stephen P. Decent
Keyword(s):  
Free Surface ◽  
Shear Thickening ◽  
Linear Instability ◽  
Liquid Jets ◽  
Liquid Jet ◽  
Long Wavelength ◽  
Droplet Sizes ◽  
Wavelength Approximation ◽  
Steady Solutions ◽  
Linear Instability Analysis

Applications of the breakup of a liquid jet into droplets are common in a variety of different industrial and engineering processes. One such process is industrial prilling, where small spherical pellets and beads are generated from the rupture of a liquid thread. In such a process, curved liquid jets produced by rotating a perforated cylindrical drum are utilized to control drop sizes and breakup lengths. In general, smaller droplets are observed as the rotation rate is increased. The addition of surfactants along the free surface of the liquid jet as it emerges from the orifice provides a possibility of further manipulating breakup lengths and droplet sizes. In this paper, we build on the work of Uddin et al. (2006, “The Instability of Shear Thinning and Shear Thickening Liquid Jets: Linear Theory,” ASME J. Fluids Eng., 128, pp. 968–975) and investigate the instability of a rotating liquid jet (having a power law rheology) with a layer of surfactants along its free surface. Using a long wavelength approximation we reduce the governing equations into a set of one-dimensional equations. We use an asymptotic theory to find steady solutions and then carry out a linear instability analysis on these solutions.

Droplet Interaction in the Liquid Injection by Multiple Orifices in the Performance of a Venturi Scrubber

2008 ◽  
Vol 591-593 ◽  
pp. 896-901 ◽  
Author(s):  
Vádila Giovana Guerra ◽  
M.A.F. Daher ◽  
M.V. Rodrigues ◽  
José Antônio Silveira Gonçalves ◽  
José Renato Coury
Keyword(s):  
Size Distribution ◽  
High Speed ◽  
Liquid Flow Rate ◽  
Experimental Tests ◽  
Liquid Jet ◽  
Gas Velocity ◽  
Venturi Scrubber ◽  
Liquid Injection ◽  
Multiple Jets ◽  
Jet Penetration

The Venturi scrubber, equipment frequently used in the removal of particles from gases, is constituted basically by a duct with a convergent section followed by a constriction, or throat, and a divergent section. A liquid, usually injected in the throat, is atomized by the flowing air at high speed. The formed droplets act as collectors of particles from the gas. The size and the size distribution of the droplets inside the equipment are therefore of great importance in the equipment performance. In the present work, the liquid jet penetration is visualized and the study of the droplet formation in a rectangular Venturi is carried out. The liquid injection is made through multiple orifices and the interaction of multiple jets is taken into account. In the experimental tests, the gas velocity in the throat, the liquid flow rate and the number of orifices for liquid injection were varied. A Malvern Spraytec aerosol analyzer was used for measuring of the droplet size and size distribution. The results showed that the liquid jet penetration influences significantly the size of the formed droplet.

scholarly journals Thermal Effect on the Instability of Annular Liquid Jet

Aerospace ◽  
2021 ◽  
Vol 8 (12) ◽  
pp. 382
Author(s):  
Xiao Cui ◽  
Boqi Jia
Keyword(s):  
Reynolds Number ◽  
Temperature Gradient ◽  
Thermal Effect ◽  
Weber Number ◽  
Marangoni Effect ◽  
Critical Value ◽  
Liquid Jet ◽  
Radial Temperature Gradient ◽  
Radial Temperature ◽  
Annular Liquid Jet

The linear instability of an annular liquid jet with a radial temperature gradient in an inviscid gas steam is investigated theoretically. A physical model of an annular liquid jet with a radial temperature gradient is established, dimensionless governing equations and boundary conditions are given, and numerical solutions are obtained using the spectral collocation method. The correctness of the results is verified to a certain extent. The liquid surface tension coefficient is assumed to be a linear function of temperature. The effects of various dimensionless parameters (including the Marangoni number/Prandtl number, Reynolds number, temperature gradient, Weber number, gas-to-liquid density ratio and velocity ratio) on the instability of the annular liquid jet are discussed. A decreasing Weber number destabilizes the annular liquid jet when the Weber number is lower than a critical value. It is found that the effects of the Marangoni effect are related to the Weber number. The Marangoni effect enhances instability when the Weber number is small, while the Marangoni effect weakens instability when the Weber number is large. In addition, because the thermal effect is considered, a decreasing Reynolds number enhances the instability when the Weber number is lower than a critical value, which is similar to the results of a viscous liquid sheet with a temperature difference between two planar surfaces. Furthermore, the effects of other dimensionless parameters are also investigated.

Experimental Study of Sprays from Annular Liquid Jet Breakup

1999 ◽  
Vol 15 (1) ◽  
pp. 103-110 ◽  
Author(s):  
Xianguo Li ◽  
Jihua Shen
Keyword(s):  
Experimental Study ◽  
Liquid Jet ◽  
Jet Breakup ◽  
Annular Liquid Jet
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