Study on the characteristic of the spray angle in pressure swirl spray atomisation

1987 ◽  
Vol 8 (5) ◽  
pp. 477-487
Author(s):  
Lu Ding-yuan
Keyword(s):  
Spray Angle ◽  
Pressure Swirl

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.

Film Thickness, Droplet Size Measurements and Correlations for Large Pressure-Swirl Atomizers

1998 ◽  
Author(s):  
M. A. Benjamin ◽  
A. Mansour ◽  
U. G. Samant ◽  
S. Jha ◽  
Y. Liao ◽  
...  
Keyword(s):  
Film Thickness ◽  
Droplet Size ◽  
Large Scale ◽  
Spray Angle ◽  
Orifice Diameter ◽  
Flow Number ◽  
Swirl Chamber ◽  
Large Pressure ◽  
Nozzle Geometries ◽  
Pressure Swirl

A parametric experimental study has been conducted to measure the discharge coefficient, the flow number, the film thickness, the spray angle, the velocity coefficient and droplet size of a large-scale simplex nozzle using ultrasonic and optical techniques. Seventeen nozzle geometries have been studied for three mass flow rates. The large-scale nozzle provides adequate resolution for measurements of film thickness, spray angle, and droplet size. The experimental data collected have been used to derive new and improved correlations for nozzle flow and breakup parameters. It is found that the atomizer constant (ratio of total inlet area to product of the swirl chamber and orifice diameter) is the primary parameter affecting the atomizer performance. As the atomizer constant increases, the discharge and velocity coefficients increase and the spray angle decreases.

Modeling of Gas-Liquid Flow in Pressure Swirl Atomizers

2005 ◽  
Author(s):  
Ashraf A. Ibrahim ◽  
Milind A. Jog
Keyword(s):  
Liquid Flow ◽  
Industrial Applications ◽  
Liquid Sheet ◽  
Spray Angle ◽  
Nozzle Geometry ◽  
Two Phase ◽  
Non Linear ◽  
Sheet Breakup ◽  
Gas Liquid Flow ◽  
Pressure Swirl

Pressure swirl or simplex atomizers are commonly used in a number of industrial applications for liquid atomization, including fuel injection systems for gas turbine engines, spray drying, and paint sprays. Computational modeling of the two-phase flow in the atomizer coupled with a non-linear analysis of instability of liquid sheet exiting from the atomizer has been carried out. The Volume-of-Fluid method is employed to determine the two-phase gas-liquid flow inside the atomizer. Results are validated using available experimental data for film thickness at exit, spray angle, and discharge coefficient. The predictions of breakup length using the non-linear model are compared with available experimental measurements which show excellent agreement. The effect of flow conditions and nozzle geometry on the flow field and sheet breakup are investigated. The coupled internal flow simulation and sheet instability analysis provides a comprehensive approach to modeling atomization from a pressure-swirl atomizer.

scholarly journals Characteristics of Spray Angle and Discharge Coefficient of Pressure-Swirl Atomizer

2021 ◽  
Vol 85 (2) ◽  
pp. 107-114
Author(s):  
Zulkifli Abdul Ghaffar ◽  
Salmiah Kasolang ◽  
Ahmad Hussein Abdul Hamid
Keyword(s):  
Discharge Coefficient ◽  
Performance Test ◽  
Spray Angle ◽  
Inverse Relation ◽  
Direct Relation ◽  
Test Rig ◽  
Gas Cooling ◽  
Swirl Atomizer ◽  
Pressure Swirl ◽  
Pressure Swirl Atomizer

A widely distributed spray is an important feature for an atomizer which is required in various applications such as gas cooling, gas turbine combustion, and fluidized bed granulator. Pressure-swirl atomizer is an example of atomizer which provides a wide spray angle through the swirling effect inside the atomizer. One of the important parameters affecting spray angle is atomizer geometrical constant, K. Another important parameter of pressure-swirl atomizer is discharge coefficient, Cd. Discharge coefficient describes the throughput of the liquid flow. An experimental test-rig was constructed to conduct the performance test of the atomizer. Acquired images were analysed using image-processing software. It was found that K has inverse relation with spray angle and direct relation with Cd. Prediction of spray angle and Cd using existing correlations also yields similar trends with the experimental results, but some parameters still need to be considered to perform an accurate prediction.

scholarly journals Effect of Low Ambient Pressure on Spray Cone Angle of Pressure Swirl Atomizer

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Zhengyan Guo ◽  
Yi Jin ◽  
Kai Zhang ◽  
Kanghong Yao ◽  
Yunbiao Wang ◽  
...  
Keyword(s):  
High Speed ◽  
Ambient Pressure ◽  
Cone Angle ◽  
Spray Angle ◽  
High Speed Photography ◽  
Spray Cone Angle ◽  
Spray Cone ◽  
Swirl Atomizer ◽  
Pressure Swirl ◽  
Pressure Swirl Atomizer

Pressure swirl atomizers are widely used in gas turbine combustor; this paper is aimed at researching the effect of low ambient pressure (0.1 MPa to 0.01 MPa, lower than an atmosphere) on the spray cone angle of pressure swirl atomizer. The spray angle is captured by high-speed photography; then, an image post program is used to process the spray angle magnitude. A mathematical model of a single droplet’s movement and trajectory based on force analysis is proposed to validate the spray angle variation. The maximum variation of the spray cone angle, which is observed when fuel supply pressure drop through the atomizer is 1 MPa as the ambient pressure decreases from 0.1 MPa to 0.01 MPa, is found to be 23.9%. The experimental results show that the spray cone angle is expected to increase with the ambient pressure decrease; meanwhile, mathematical results agree well with this trend.

scholarly journals Design and construction of the pressure swirl nozzle and experimental investigation of spray characteristics

2019 ◽  
Vol 13 (3) ◽  
pp. 204-212
Author(s):  
Seyed Hadi Seyedin ◽  
Majid Ahmadi ◽  
Seyed Vahid Seyedin
Keyword(s):  
Image Processing ◽  
Digital Camera ◽  
Air Pressure ◽  
Spray Angle ◽  
Orifice Diameter ◽  
Measuring Time ◽  
Total Measuring Time ◽  
Liquid Atomization ◽  
And Performance ◽  
Pressure Swirl

This paper focuses on the structure and performance of the pressure swirl nozzle and the study of liquid atomization. In this study, the atomizer has been designed and some experiments have been performed on it. Since image processing is an efficient method for measuring the size of the droplet and since it considerably reduces the total measuring time and eliminates the subjective observer’s error in sizing and counting spray drops, a digital camera has been used for capturing images and image processing has been done by the MATLAB software. The results show that by increasing the atomization air pressure, the spray angle increases and the droplet’s size decreases. It is concluded that the spray angle is a function of the atomization air pressure and orifice diameter. Moreover, when the distance from the spray centre line increases, the droplet’s average velocity decreases.

The Spray Angle Improvement of Single Inlet Pressure Swirl Atomizer Using Partial Structure Modifying

2011 ◽  
Vol 189-193 ◽  
pp. 31-37 ◽  
Author(s):  
Ji Liang Wu ◽  
De Yuan Zhang ◽  
Xing Gang Jiang
Keyword(s):  
Inlet Pressure ◽  
Spray Angle ◽  
Partial Structure ◽  
Swirl Chamber ◽  
Swirl Atomizer ◽  
Pressure Swirl ◽  
Dynamics Method ◽  
Pressure Swirl Atomizer ◽  
Outlet Orifice

This paper analyzed the velocity field of the section between outlet orifice and the conical swirl chamber with a kind of single inlet pressure atomizer using CFD (Computational Fluid Dynamics) method. A method of modifying the outlet orifice position referring to the swirl chamber in order to improve the spray angle and its homogeneity is proposed. The result of the experiments shows that it is a feasible method to improve the quality of this kind of atomizer.

ESTIMATION OF THE BREAKUP LENGTH FOR A PRESSURE-SWIRL SPRAY FROM THE EXPERIMENTALLY MEASURED SPRAY ANGLE

2009 ◽  
Vol 19 (3) ◽  
pp. 235-246 ◽  
Author(s):  
Seoksu Moon ◽  
Choongsik Bae ◽  
Essam F. Abo-Serie
Keyword(s):  
Spray Angle ◽  
Breakup Length ◽  
Pressure Swirl

Effect of Dimensionless Numbers on Air Core Diameter of Pressure-Swirl Atomizer

2020 ◽  
Vol 899 ◽  
pp. 22-28
Author(s):  
Zulkifli Abdul Ghaffar ◽  
Salmiah Kasolang ◽  
Ahmad Hussein Abdul Hamid ◽  
Mohd Syazwan Firdaus Mat Rashid
Keyword(s):  
Performance Test ◽  
Operating Conditions ◽  
Spray Angle ◽  
Dimensionless Numbers ◽  
Flow Area ◽  
Core Diameter ◽  
Air Core ◽  
Swirl Atomizer ◽  
Pressure Swirl ◽  
Pressure Swirl Atomizer

Air core is an important parameter in pressure swirl atomizer since formation of air core determines the thickness of the discharged liquid sheet and the effective flow area of nozzle discharge. This consequently will affect the coefficient of discharge and the spray angle. This study conducted for the investigation of the relation between dimensionless numbers on the air core diameter. Dimensionless numbers are helpful aid for the quantification of independent parameters involving atomizer design and operating conditions simultaneously. Reynolds number, Re and orifice-to-swirl chamber diameter ratio, N are the dimensionless numbers selected for this study. Despite of the availability of study on the effect of dimensionless numbers on air core diameter, more study requires especially for smaller N. An experimental test-rig was constructed to conduct the performance test of the atomizer. Acquired images were analyzed using image-processing software. It was found that N has more significant effect on the change of air core diameter compared to Re. However, it is observed that at Re = 40000, N = 0.07 produces almost similar air core diameter with N = 0.25 at Re < 20000. In contrast, with N = 0.5, air core diameter produces are larger even at Re < 20000. Hence, it can be concluded that both Re and N are important parameters in characterizing the air core diameter in pressure-swirl atomizer.

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