EFFECTS OF NOZZLE EXIT GEOMETRY ON SPRAY CHARACTERISTICS OF A BLURRY INJECTOR

2013 ◽  
Vol 23 (3) ◽  
pp. 193-209 ◽  
Author(s):  
Claudia Goncalves Azevedo ◽  
Jose Carlos de Andrade ◽  
Fernando de Souza Costa
Keyword(s):  
Nozzle Exit ◽  
Spray Characteristics

Experimental investigation on fluid structure and full-cone spray characteristics of a jet-swirl atomizer using shadowgraph technique

2021 ◽  
pp. 095441002110376
Author(s):  
Mazyar Shafaee ◽  
Abbas Elkaie ◽  
Mohammad Amin Hassani
Keyword(s):  
Nozzle Exit ◽  
Uniform Structure ◽  
Spray Parameters ◽  
Number Density ◽  
Spray Characteristics ◽  
Spray Cone ◽  
Fluid Structure ◽  
Spray Density ◽  
Mean Diameter ◽  
Swirl Atomizer

Full-cone spray is quite important in spray cooling and catalytic combustion applications; however, it is not extensively studied. Besides, the liquid spray is relatively a non-uniform structure especially along longitudinal axis which includes different sizes and distribution of droplets. The few published experimental studies are limited to calculate some of the spray characteristics on a certain plane located downstream of the nozzle exit. Therefore, the spray parameters representing fluid structure, droplets mean diameter, and their distribution in different cross sections from nozzle exit are considered in this study. Accordingly, a jet-swirl atomizer with pressure-swirl full-cone spray is investigated where all important full-cone spray characteristics are considered at different planes from nozzle exit. The spray images are obtained with a shadowgraph technique and are analyzed to obtain the Sauter mean diameter (SMD), D10, and droplet size distribution along with the spray structure, spray cone angle, and discharge coefficient. The experimental results are verified based on the pre-published numerical studies on the same atomizer. The experimental and numerical results show good agreement. Moreover, the results show that the SMD is increased by moving away from center of spray to its edges, and the droplets number density is increased in central regions. The increased droplets number density leads to the greater external forces which create smaller droplets. In contrast, larger particles exist in peripheral parts due to the less droplets concentration. Furthermore, and far away from the exit nozzle, the SMD values are decreased due to the increased aerodynamic forces and oscillations. The droplets dispersion including spray density in radial and axial directions is also observed using spray density images.

Swirl and Counterswirl Effects in Prefilming Airblast Atomizers

1988 ◽  
Vol 110 (1) ◽  
pp. 105-110 ◽  
Author(s):  
M. Aigner ◽  
S. Wittig
Keyword(s):  
Shear Flow ◽  
Size Distribution ◽  
Nozzle Exit ◽  
Drop Size ◽  
Recirculation Zone ◽  
Drop Size Distribution ◽  
Shear Stresses ◽  
Spray Characteristics ◽  
Air Supply

The performance characteristics of prefilming airblast atomizers depend largely on the shear stresses in each of the two air supply channels. As an extension of previously reported results, experiments were conducted using an atomizer model with separately controlled air ducts and typical prototype nozzles. It was shown that the quality of atomization can be limited due to internal droplet formation. However, the velocity profiles of the atomization air and the properties of the liquid are the dominant parameters that determine the drop-size distribution generated at the atomization edge. The shear flow at the nozzle exit and the recirculation zone depend largely on the swirl or counterswirl of the exiting air. Correlations have been obtained between the spray characteristics and the relevant parameters.

scholarly journals Potential for Shock-Wave Generation at Diesel Engine Conditions and Its Influence on Spray Characteristics

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6465
Author(s):  
Weidi Huang ◽  
Huifeng Gong ◽  
Raditya Hendra Pratama ◽  
Seoksu Moon ◽  
Keiji Takagi ◽  
...  
Keyword(s):  
Shock Wave ◽  
Diesel Engine ◽  
Nozzle Exit ◽  
Fuel Injection ◽  
Injection Pressure ◽  
Wave Generation ◽  
Contrast Imaging ◽  
Spray Characteristics ◽  
Supersonic Part ◽  
Shock Wave Generation

Increasing the fuel injection pressure is currently the most effective way to achieve a better fuel–air mixing quality in modern engines. Systems capable of delivering fuels at a pressure of over 250 MPa have been widely adopted in diesel engines. At such high injection pressures, the shock-wave generation during fuel injection has been noticed. Investigations can be found widely discussing on how the shock-wave generation during fuel injection would affect the spray dynamics. However, the argument remains whether the shock wave can occur at diesel engine conditions since the diesel engine is operated at very high ambient temperature and density. Even if it could occur, how significantly the spray-induced shock wave affects the spray characteristics is rarely known. To address these concerns, this study was proposed. First, experiments were conducted to obtain the detailed spray dynamics from the nozzle exit to spray downstream field by taking advantage of the X-ray phase-contrast imaging (XPCI) and schlieren imaging techniques. It is found that supersonic and subsonic ligaments coexist in one spray. Increasing the injection pressure or reducing the ambient density would extend the supersonic part in the spray. Multiple shock waves occur subsequently from the nozzle exit, where the spray has the highest local velocity. Shock-wave generation during fuel injection could enhance spray penetration, whereas this effect depends on the length of the supersonic part in the spray. Finally, a diagram was proposed to predict the potential for the shock-wave generation and discuss the possible effect on spray characteristics at diesel engine conditions.

EFFECT OF RECESS LENGTH ON THE SPRAY CHARACTERISTICS OF LIQUID-CENTERED SWIRL COAXIAL INJECTORS

2016 ◽  
Vol 26 (6) ◽  
pp. 535-550 ◽  
Author(s):  
Qinglian Li ◽  
Zhongtao Kang ◽  
Xinqiao Zhang ◽  
Peng Cheng
Keyword(s):  
Spray Characteristics

DECOUPLING THE EFFECT OF SURFACE TENSION AND VISCOSITY ON SPRAY CHARACTERISTICS UNDER DIFFERENT AMBIENT PRESSURES: NEAR-NOZZLE BEHAVIOR AND MACROSCOPIC CHARACTERISTICS

2019 ◽  
Vol 29 (7) ◽  
pp. 629-654
Author(s):  
Zehao Feng ◽  
Shangqing Tong ◽  
Chenglong Tang ◽  
Cheng Zhan ◽  
Keiya Nishida ◽  
...  
Keyword(s):  
Surface Tension ◽  
Spray Characteristics ◽  
Effect Of Surface

EFFERVESCENT ATOMIZATION OF POLYVINYLPYRROLIDONE SOLUTIONS: INFLUENCE OF LIQUID PROPERTIES AND ATOMIZER GEOMETRY ON LIQUID BREAKUP AND SPRAY CHARACTERISTICS

2013 ◽  
Vol 23 (1) ◽  
pp. 1-23 ◽  
Author(s):  
Jewe Schroder ◽  
Astrid Gunther ◽  
Karl-Ernst Wirth ◽  
Heike P. Schuchmann ◽  
Volker Gaukel
Keyword(s):  
Spray Characteristics

GEOMETRIC EFFECT ON SPRAY CHARACTERISTICS OF GAS-CENTERED SWIRL COAXIAL INJECTORS: RECESS RATIO AND GAP THICKNESS

2017 ◽  
Vol 27 (7) ◽  
pp. 579-589 ◽  
Author(s):  
Gujoeng Park ◽  
Jungho Lee ◽  
Ingyu Lee ◽  
Youngbin Yoon ◽  
Chae Hoon Sohn
Keyword(s):  
Spray Characteristics ◽  
Geometric Effect

EXPERIMENTAL APPROACHES TO INVESTIGATING LIQUEFIED LPG SPRAY CHARACTERISTICS

2010 ◽  
Vol 20 (6) ◽  
pp. 553-564 ◽  
Author(s):  
Kwan-Soo Lee ◽  
Ki-Hyung Lee ◽  
Ki-Bum Kim ◽  
Yung-Jin Kim
Keyword(s):  
Spray Characteristics ◽  
Experimental Approaches
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