scholarly journals Influence of nozzle outlet diameter on the atomization process of zirconia dry granulation

2021 ◽  
Vol 13 (6) ◽  
pp. 168781402110248
Author(s):  
Dongling Yu ◽  
Zuoxiang Zhu ◽  
Jiangen Zhou ◽  
Dahai Liao ◽  
Nanxing Wu
Keyword(s):  
Liquid Film ◽  
Cone Angle ◽  
Nozzle Outlet ◽  
Atomization Process ◽  
Spray Cone Angle ◽  
Spray Cone ◽  
Dry Granulation ◽  
Air Core ◽  
Atomization Characteristics ◽  
Pressure Swirl

In order to predict the atomization characteristics of the atomization process of zirconia dry granulation accurately, the influence of nozzle outlet diameter on the atomization characteristics of the atomization process of zirconia dry granulation is analyzed. The VOF method and RNG k-ε turbulence model are applied to numerically analyze the flow field of pressure-swirl nozzles with different outlet diameters of the atomization process of zirconia dry granulation, and the effects of outlet diameters on the spray cone angle, liquid film thickness, pressure distribution and velocity distribution are analyzed. The result shows that when the outlet diameter is increased from 3 to 4 mm, the diameter of air core and the outlet velocity of atomized liquid are increased, the spray cone angle is increased from 30.5° to 59.7° while the liquid film thickness is decreased, but when the outlet diameter is increased to 5 mm, the diameter of air core and the outlet velocity of atomized liquid are decreased, the spray cone angle is decreased to 27.6°, while the thickness of liquid film is decreased. The spray cone angle, moisture content of zirconia particles corresponding to nozzles with different outlet diameters are measured by the design of atomization experiment platform and the microstructure of zirconia particles are observed, which verifies the correctness of numerical analysis. Taking the atomization performance of nozzle into consideration, the pressure-swirl nozzle with the outlet diameter of 4 mm is better suitable for the atomization process of zirconia dry granulation.

Effect of nozzle inlet parameters on the dry granulation atomization process of Si3N4 ceramic bearing balls

2021 ◽  
Vol 12 (06) ◽  
pp. 2150058
Author(s):  
Dongling Yu ◽  
Xiaohui Zhang ◽  
Hongbin Luo ◽  
Dahai Liao ◽  
Nanxing Wu
Keyword(s):  
Deflection Angle ◽  
Cone Angle ◽  
Spray Cone Angle ◽  
Spray Cone ◽  
Dry Granulation ◽  
Air Core ◽  
Mean Diameter ◽  
The Mean ◽  
The Deflection Angle ◽  
Pressure Swirl

In this paper, the atomization characteristics of Si3N4 ceramic dry granulation affect the performance of Si3N4 ceramic bearing balls. In order to improve the dry granulation characteristics and the comprehensive performance of Si3N4 ceramic bearing balls, the atomization mechanism of the spinning nozzle used for Si3N4 dry granulation was studied in detail. The interaction between air and binder in the pressure-swirl nozzle is analyzed based on VOF method, the modified realizable [Formula: see text] turbulence model is used to simulate the flow field inside and outside the pressure-swirl nozzle, the effects of nozzle inlet parameters including the number of tangential inlets and the deflection angle of tangential inlets on the binder volume fraction, velocity distribution and pressure distribution are analyzed. The results show that when the number of tangential inlets increases from 1 to 4, the swirl strength of gas–liquid two-phase in the nozzle increases, the mean diameter of air core increases from 1.51[Formula: see text]mm to 2.01[Formula: see text]mm, and the spray cone angle increases from 18.5[Formula: see text] to 26.4[Formula: see text]. Besides, when the deflection angle of tangential inlet increases from 0[Formula: see text] to 15[Formula: see text], the swirl strength of gas–liquid two-phase in the nozzle with the deflection angle of tangential inlet of 10[Formula: see text] is the largest, and the mean diameter of air core and spray cone angle is 3.04[Formula: see text]mm and 30.7[Formula: see text], respectively. Based on the atomization experiment platform of the electric control fuel system, the mean diameter of air core and spray cone angle are measured, the micromorphology of Si3N4 particles is observed, which verifies the correctness of numerical simulation. When the Si3N4 particles are prepared by dry granulation, taking the atomization performance of nozzle into consideration, the pressure-swirl nozzle with 4 tangential inlets and 10[Formula: see text] deflection angle should be selected.

Effect of Geometry of Pressure-Swirl Duplex Nozzle and ALR on Atomization Characteristics of Jet A-1 Fuel

2019 ◽  
Author(s):  
M. M. Hasan ◽  
R. Chandrahasan ◽  
S. Ru ◽  
Y. Choi ◽  
J. Lee
Keyword(s):  
Cone Angle ◽  
Rotating Flow ◽  
Spray Characteristics ◽  
Spray Cone Angle ◽  
Spray Cone ◽  
Internal Geometry ◽  
Fuel Atomization ◽  
Image Velocimetry ◽  
Atomization Characteristics ◽  
Pressure Swirl

Abstract The efficiency of engine combustion is strongly dependent on fuel atomization and spray processes which in turn are greatly influenced by nozzle internal geometry and parameter like air to liquid ratio (ALR). Modern engines employ different geometrically designed nozzles. It is crucial to characterize the effect of the internal geometry of the nozzle and ALR on atomization characteristics. In this study, the effects of geometric parameters of the pressure-swirl duplex nozzle and ALR on the spray characteristics of Jet A-1 fuel were investigated. Two different shaped pilot nozzles and two different shaped main nozzles were used. The analysis of spray characteristics was done by using particle image velocimetry (PIV) system and phase Doppler anemometry (PDA) system. Spray cone angle, Sauter mean diameter (SMD) distribution and weighted mean SMD (WMSMD) were analyzed. In the case of the effect of the internal geometry of the nozzle, the results show that when main and pilot nozzle work together, it produces a higher spray cone angle compared to the pilot nozzle alone. Cone-shaped pilot nozzle tip exhibits better atomization characteristic than flat shaped pilot nozzle tip. Combined main and pilot nozzle with counter-rotating flow provides smaller droplets and higher spray cone angle than co-rotating flow configuration. In the case of the effect of ALR, a decreasing trend in the spray cone angle is found with increasing ALR. Moreover, WMSMD increases with increasing ALR up to 1.16, but thereafter, it decreases again.

Experimental investigations on atomization characteristics of dual-orifice atomizers part I: Optimization method formation

2020 ◽  
pp. 095765092096161
Author(s):  
Xiongjie Fan ◽  
Cunxi Liu ◽  
Yong Mu ◽  
Yulan Wang ◽  
Kaixing Wang ◽  
...  
Keyword(s):  
Liquid Film ◽  
Mass Flow ◽  
Cone Angle ◽  
Structural Parameter ◽  
Main Stage ◽  
Structure Parameters ◽  
Spray Cone Angle ◽  
Spray Cone ◽  
Atomization Characteristics ◽  
Secondary Separation

In this paper, influences of structure parameters on mass flow and atomization characteristics (spray cone angle, SMD, liquid film fusion and separation) of dual-orifice atomizers were investigated using Fraunhofer diffraction optical instrument and high-speed shadowgraph technique. The main influential structure parameters are obtained by structural parameter sensitivity analysis. Liquid film fusion and separation is an important atomization characteristic lacking of in-depth research. Results of liquid film fusion and separation illustrate that three patterns (separation-fusion-secondary separation) of main stage liquid film and pilot stage liquid film appear with the increase of Δ P. Liquid film fusion makes SMD larger, and there is a delay in liquid film separation when reduce Δ P after liquid film fusion. In addition, mass flow and spray cone angle are key factors which affect liquid film fusion pressure, liquid film secondary separation pressure and distance between two liquid films. The smaller the pilot stage mass flow is, the larger the effect of the main stage on pilot stage spray cone angle will be. Results in this paper could be used to the design and optimization of new dual-orifice atomizers.

scholarly journals Experimental Study of Spray Characteristics of Kerosene-Ethanol Blends from a Pressure-Swirl Nozzle

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Tao Zhang ◽  
Bo Dong ◽  
Xun Zhou ◽  
Linan Guan ◽  
Weizhong Li ◽  
...  
Keyword(s):  
Discharge Coefficient ◽  
Cone Angle ◽  
Injection Pressure ◽  
Spray Characteristics ◽  
Spray Cone Angle ◽  
Spray Cone ◽  
Breakup Length ◽  
Ethanol Blends ◽  
Pressure Swirl ◽  
Spray Velocity

Partial replacement of kerosene by ethanol in a gas turbine is regarded as a good way to improve the spray quality and reduce the fossil energy consumption. The present work is aimed at studying the spray characteristics of kerosene-ethanol blends discharging from a pressure-swirl nozzle. The spray cone angle, discharge coefficient, breakup length, and velocity distribution are obtained by particle image velocimetry, while droplet size is acquired by particle/droplet imaging analysis. Kerosene, E10 (10% ethanol, 90% kerosene), E20 (20% ethanol, 80% kerosene), and E30 (30% ethanol, 70% kerosene) have been considered under the injection pressure of 0.1–1 MPa. The results show that as injection pressure is increased, the discharge coefficient and breakup length decrease, while the spray cone angle, drop size, and spray velocity increase. Meanwhile, the drop size decreases and the spray velocity increases with ethanol concentration when the injection pressure is lower than 0.8 MPa. However, the spray characteristics are not affected obviously by the ethanol concentration when the injection pressure exceeds 0.8 MPa. A relation to breakup length for kerosene-ethanol blends is obtained. The findings demonstrate that the adding of ethanol into kerosene can promote atomization performance.

Experimental Study on Spray Pattern of Pressure-Swirl Nozzle in Reactor Containment

2018 ◽  
Author(s):  
Jiawei Bian ◽  
Dalin Zhang ◽  
Rulei Sun ◽  
Yingwei Wu ◽  
Wenxi Tian ◽  
...  
Keyword(s):  
Experimental Study ◽  
Optimization Design ◽  
Flux Distribution ◽  
Cone Angle ◽  
Distribution Models ◽  
Spray Droplet ◽  
Spray Cone Angle ◽  
Spray Cone ◽  
Spray Field ◽  
Pressure Swirl

Spraying system plays an important role in the safety of PWR. To ensure homogeneous spraying of the containment, the layout of nozzles on the spray header was taken into consideration in design. In this paper, an experimental study was conducted to obtain spray characteristics data, including spray cone angle and 2-D spray flux distribution for the purpose of achieving optimal design of the spraying system. According to the specialty of the spray field involved, a testing loop with four pressure-swirl nozzles was established for the study. Spray cone angles were obtained by photograph method. The volume flux distribution was measured by collecting the spray droplet along the cross-section diameters. Based on the experimental data, typical spray flux distributions were obtained. The flux distribution results were used to build 3-D coverage models. Then these models were used to calculate the overall spray coverage in the containment. The present work introduces the experimental study of spray behavior of a typical pressure-swirl nozzle in containment and the method to evaluate spray coverage through building 3-D spray flux distribution models. The work is expected to be helpful for the optimization design of spraying systems.

Experimental investigations on atomization characteristics of dual-orifice atomizers part II: Optimization method application

2020 ◽  
pp. 095765092095996
Author(s):  
Xiongjie Fan ◽  
Cunxi Liu ◽  
Fuqiang Liu ◽  
Qianpeng Zhao ◽  
Jinhu Yang ◽  
...  
Keyword(s):  
Liquid Film ◽  
Mass Flow ◽  
Cone Angle ◽  
Optimization Method ◽  
Experimental Investigations ◽  
Structure Parameters ◽  
Spray Cone Angle ◽  
Spray Cone ◽  
Design And Optimization ◽  
Expansion Angle

In this paper, the optimization method we obtained from dual-orifice atomizers previously is used to design and optimize new dual-orifice atomizers, whereas there are some differences between the new dual-orifice atomizer and dual-orifice atomizer used in Part I. For example, the mass flow is much smaller, there is an expansion angle at pilot nozzle to regulate pilot stage spray cone angle, and there is no recess length between main nozzle and pilot nozzle. Influences of structure parameters on mass flow, spray cone angle and liquid film fusion and separation are investigated, which are consistent with the expectation. Structure parameters that meet performance requirements of dual-orifice atomizer are analyzed. In addition, a new phenomenon has been found is that liquid film oscillation appears with the increase of Δ P, which should be avoided during the design and optimization of new atomizers. Pilot liquid film oscillation will influence the development of dual-orifice liquid film. Pilot swirling groove depth and expansion angle of pilot nozzle are key parameters that influence liquid film oscillation. Conclusions in this paper can be used to guide the design and optimization of new dual-orifice atomizers.

Influence of Ambient Air Pressure on Pressure-Swirl Atomization

1987 ◽  
Author(s):  
X. F. Wang ◽  
A. H. Lefebvre
Keyword(s):  
Drop Size ◽  
Cone Angle ◽  
Ambient Air ◽  
Air Pressure ◽  
Spray Angle ◽  
Flow Number ◽  
Spray Cone Angle ◽  
Spray Cone ◽  
Continuous Increase ◽  
Pressure Swirl

The spray characteristics of six simplex atomizers are examined in a pressure vessel using a standard light diffraction technique. Attention is focused on the effects of liquid properties, nozzle flow number, spray cone angle, and ambient air pressure on mean drop size and drop-size distribution. For all nozzles and all liquids it is found that continuous increase in air pressure above the normal atmospheric value causes the SMD to first increase up to a maximum value and then decline. An explanation for this characteristic is provided in terms of the measurement technique employed and the various competing influences on the overall atomization process. The basic effect of an increase in air pressure is to improve atomization, but this trend is opposed by contraction of the spray angle which reduces the relative velocity between the drops and the surrounding air, and also increases the possibility of droplet coalescence.

Spray Performance of Alternative Jet Fuel Based Nanofuels at High-Ambient Conditions

2018 ◽  
Author(s):  
Mohamed Soltan ◽  
Buthaina Al Abdulla ◽  
AlReem Al Dosari ◽  
Kumaran Kannaiyan ◽  
Reza Sadr
Keyword(s):  
Ambient Pressure ◽  
Cone Angle ◽  
Jet Fuel ◽  
Liquid Sheet ◽  
Ambient Conditions ◽  
Spray Characteristics ◽  
Atomization Process ◽  
Spray Cone Angle ◽  
Spray Cone ◽  
Sheet Breakup

Dispersion of nanoparticles in pure fuels alters their key fuel physical properties, which could affect their atomization process, and in turn, their combustion and emission characteristics in a combustion chamber. Therefore, it is essential to have a thorough knowledge of the atomization characteristics of nanofuels (nanoparticles dispersed in pure fuels) to better understand their latter processes. This serves as the motivation for the present work, which attempts to gain a good understanding of the atomization process of the alternative, gas-to-liquid (GTL), jet fuel based nanofuels. The macroscopic spray characteristics such as spray cone angle, liquid sheet breakup, and liquid sheet velocity are determined by employing shadowgraph imaging technique. The effect of nanoparticles weight concentration and ambient pressures on the spray characteristics are investigated in a high pressure-high temperature constant volume spray rig. To this end, a pressure swirl nozzle with an exit diameter of 0.8 mm is used to atomize the fuels. The macroscopic spray results demonstrate that the nanoparticles dispersion at low concentrations affect the near nozzle region. The spray liquid sheet breakup distance is reduced by the presence of nanoparticle due to the early onset of disruption in the liquid sheet. Consequently, the liquid sheet velocity in that spray region is higher for nanofuels when compared to that of pure fuels. Also, the ambient pressure has a significant effect on the spray features as reported in the literature.

Sign in / Sign up

Export Citation Format

Share Document