Spray Characteristics of Elliptical Power-Law Fluid-Impinging Jets

2017 ◽  
Vol 139 (7) ◽  
Author(s):  
Fei Zhao ◽  
Li-Zi Qin ◽  
Qing-Fei Fu ◽  
Chao-Jie Mo ◽  
Li-Jun Yang
Keyword(s):  
Power Law ◽  
Impinging Jets ◽  
Liquid Sheet ◽  
Rheological Parameters ◽  
Power Law Fluid ◽  
Spray Characteristics ◽  
Theoretical Predictions ◽  
Fluid Jets ◽  
Atomization Efficiency ◽  
Improved Model

The spray characteristics of a liquid sheet contribute much to the investigation of atomization efficiency. Considering the jet contracting effect of elliptical jets, an improved model of elliptical power-law fluid jets is proposed herein to derive the spray characteristics. Some experiments have been conducted to verify its feasibility, and the results show a good agreement with theoretical predictions. The effect of the aspect ratio on sheet shape and thickness has been studied to interpret the phenomenon that liquid sheets formed by the impinging elliptical jets are more likely to disintegrate. The relationships between rheological parameters (K and n) and the spray features are also discussed.

Study on some Aspects of Breakup Characteristics of Power-Law Fluid with Impinging Jets Based on Mechanics Properties

2012 ◽  
Vol 625 ◽  
pp. 57-60
Author(s):  
En Dong Wang ◽  
Yan Yin ◽  
Qing Du
Keyword(s):  
Power Law ◽  
High Speed ◽  
Wave Length ◽  
Impinging Jets ◽  
Liquid Sheet ◽  
Liquid Jets ◽  
Power Law Fluid ◽  
Round Jets ◽  
Breakup Length ◽  
Jet Velocity

Shear-thinning power-law fluid is a kind of non-Newtonian fluid in which the viscosity is a function of shear rate. Impinging jets system is used to study the breakup characteristics of power-law liquid sheets formed by two symmetrical round jets in this study. High quality images are obtained from the experiment with a high speed camera and breakup length is extracted from the images. Closed-rim sheet, web-like sheet and ligaments sheet are observed with the increase of jet velocity. A series of images show that the wave length on the surface of sheets tends to decline as the jet velocity increases. At a low We number, the breakup length increases with an increasing We number. However, it first increases and then decreases when the liquid sheet breaks up at a high We number. The liquid jets with larger diameter collide to each other and lead to a liquid sheet with a smaller breakup length.

A Numerical Model for Edge Effect Correction of the Mooney Rheometer

2009 ◽  
Vol 82 (4) ◽  
pp. 401-417
Author(s):  
Sergio A. Montes
Keyword(s):  
Experimental Data ◽  
Edge Effect ◽  
Power Law ◽  
Power Law Fluid ◽  
One Dimensional ◽  
Complex Shear ◽  
Theoretical Predictions ◽  
Power Law Index ◽  
Significant Concentration ◽  
Finite Difference Techniques

Abstract The flow of a power law fluid within the cavity of a multi-speed Mooney rheometer is studied by means of finite difference techniques with the aim of quantifying the edge effects that occur in the vicinity of the rotor corner. As expected, a significant concentration of shear stress occurs near the rotor edge. As the power law index varies, significant stagnation zones are found within the cavity, which combined with thin-shearing behavior near the moving surfaces, yield complex shear rate distributions. However, when torque is calculated, the edge effect can be described by a factor which is numerically very similar to a factor obtained from one-dimensional models described in the literature. Comparison of theoretical predictions and experimental data was found to be satisfactory.

scholarly journals Penetration Grouting Mechanism of Time-Dependent Power-Law Fluid for Reinforcing Loose Gravel Soil

Minerals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1391
Author(s):  
Tingting Guo ◽  
Zhiwei Zhang ◽  
Zhiquan Yang ◽  
Yingyan Zhu ◽  
Yi Yang ◽  
...  
Keyword(s):  
Numerical Calculation ◽  
Numerical Simulations ◽  
Power Law ◽  
Three Dimensional ◽  
Time Dependent ◽  
Rheological Parameters ◽  
Power Law Fluid ◽  
Dependent Behavior ◽  
Gravel Soil ◽  
Penetration Grouting

The time-dependent behavior of power-law fluid has a significant influence on the grouting effects of reinforcing loose gravel soil. In this paper, based on basic rheological equations and the time-dependent behavior of rheological parameters (consistency coefficient and rheological index), rheological equations and penetration equations of time-dependent power-law fluid are proposed. Its penetration grouting diffusion mechanism for reinforcing loose gravel soil was then theoretically induced. A set of indoor experimental devices for simulating penetration grouting was designed to simulate the penetration grouting of power-law fluid with different time-dependent behaviors for reinforcing loose gravel soil. Then, relying on the COMSOL Multiphysics platform and Darcy’s law, three-dimensional numerical calculation programs for this mechanism were obtained using secondary-development programming technology. Thus, the numerical simulations of the penetration grouting process of power-law fluid with different time-dependent behaviors for reinforcing loose gravel soil were carried out. This theoretical mechanism was validated by comparing results from theoretical analyses, indoor experiments, and numerical simulations. Research results show that the three-dimensional numerical calculation programs can successfully simulate the penetration diffusion patterns of a time-dependent power-law fluid in loose gravel soil. The theoretical calculation values and numerical simulation values of the diffusion radius obtained from this mechanism are closer to indoor experimental values than those obtained from the penetration grouting diffusion theory of power-law fluid without considering time-dependent behavior. This mechanism can better reflect the penetration grouting diffusion laws of a power-law fluid in loose gravel soil than the theory, which can provide theoretical support and guidance for practical grouting construction.

scholarly journals Numerical Simulation of Like and Unlike Impinging Jets

2017 ◽  
Author(s):  
Azadeh Kebriaee ◽  
Hamed Dolatkhahi ◽  
Ghader Oliaee
Keyword(s):  
Numerical Simulation ◽  
Adaptive Mesh Refinement ◽  
Adaptive Mesh ◽  
Impinging Jets ◽  
Liquid Sheet ◽  
Impact Behavior ◽  
Injection Speed ◽  
Two Fluids ◽  
Fluid Jets ◽  
The Impact

In the present study, using the open source OpenFOAM code, a numerical simulation is performed taking the adaptive mesh refinement (AMR) technique during solution. Formation of liquid sheet after the impact of two identical cylindrical jets at various conditions is studied. Since the flow pattern depends upon the Reynolds and Weber numbers, numerical tests are conducted at a variety of flow velocities and Reynolds numbers to demonstrate the effect of these parameters on the sheet formation. It is then concluded that at various conditions, different instabilities occur in the flow; hence, different sheet formations a flow patterns happen.In this study, impact of two dissimilar cylindrical fluid jets is successfully simulated for the first time in literature. Actually, water and oil jets are taken into account and their impact behavior is studied. In the presence of the surrounding air, an unstable sheet will form after impact due to the high injection speed of the jets. As depicted in the results, since the inertia and other physical characteristics of the two fluids are dissimilar, different phases are more intensely diffused.DOI: http://dx.doi.org/10.4995/ILASS2017.2017.4865

Experimental investigation on the spray characteristics of power-law fluid in a swirl injector

2017 ◽  
Vol 49 (3) ◽  
pp. 035508 ◽  
Author(s):  
Fuqiang Bai ◽  
Qing Chang ◽  
Shixing Chen ◽  
Jinpeng Guo ◽  
Kui Jiao ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Power Law ◽  
Power Law Fluid ◽  
Spray Characteristics ◽  
Swirl Injector

An experimental study on the atomization characteristics of impinging jets of power law fluid

2015 ◽  
Vol 217 ◽  
pp. 49-57 ◽  
Author(s):  
Yong-cui Ma ◽  
Fu-qiang Bai ◽  
Qing Chang ◽  
Ji-ming Yi ◽  
Kui Jiao ◽  
...  
Keyword(s):  
Experimental Study ◽  
Power Law ◽  
Impinging Jets ◽  
Power Law Fluid ◽  
Atomization Characteristics

Oblique Collision of Two Power-Law Fluid Jets at Low Speed

2015 ◽  
Vol 31 (6) ◽  
pp. 1653-1660 ◽  
Author(s):  
Fei Zhao ◽  
Li-jun Yang ◽  
Qing-fei Fu ◽  
Chao-jie Mo ◽  
Xue-de Li
Keyword(s):  
Power Law ◽  
Power Law Fluid ◽  
Oblique Collision ◽  
Low Speed ◽  
Fluid Jets

Stability of an annular power-law liquid sheet

2014 ◽  
Vol 229 (15) ◽  
pp. 2750-2759 ◽  
Author(s):  
Lijun Yang ◽  
Minglong Du ◽  
Qingfei Fu
Keyword(s):  
Stability Analysis ◽  
Power Law ◽  
Temporal Stability ◽  
Sheet Thickness ◽  
Momentum Equation ◽  
Liquid Sheet ◽  
Rheological Parameters ◽  
Stream Velocity ◽  
Gas Streams ◽  
Outer Interface

Because of the mathematical difficulties dealing with the nonlinear viscous stress term in momentum equation for power-law liquid, the study of stability analysis of a power-law liquid sheet has been lacking. In the present study, a temporal stability analysis has been carried out for an annular power-law liquid sheet exposed to both inner and outer-gas streams, by integrating the governing equations for the power-law liquid sheet. The dimensionless dispersion equation that governs the instability of liquid sheet is obtained by considering the velocity profile of liquid sheet. It is found that the instability of liquid sheet can be enhanced by independently increasing either the outer gas stream velocity, or the inner gas stream velocity. The liquid sheet is more unstable when both inner and outer gas streams are applied. To promote the instability of annular liquid sheet, a gas stream applied to the outer interface is more effective than when applied to the inner surface. The effects of rheological parameters on the instability of the liquid sheet are actually determined by the relative velocity across the gas–liquid interfaces. The surface tension, liquid sheet thickness, and outer surface radius of annular liquid sheet have been tested for their influence on the instability of annular power-law liquid sheet.

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