DISCHARGE COEFFICIENT AND SPRAY ANGLE MEASUREMENTS FOR SMALL PRESSURE-SWIRL NOZZLES

1994 ◽  
Vol 4 (3) ◽  
pp. 351-367 ◽  
Author(s):  
Cesar Dopazo ◽  
Javier Ballester
Keyword(s):  
Discharge Coefficient ◽  
Spray Angle ◽  
Small Pressure ◽  
Angle Measurements ◽  
Pressure Swirl

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.

A COMPARISON OF SPRAY ANGLE MEASUREMENTS USING OPTICAL AND MECHANICAL METHODS

2010 ◽  
Vol 20 (1) ◽  
pp. 85-92 ◽  
Author(s):  
Yudaya R. Sivathanu ◽  
Jongmook Lim ◽  
Bill Wallace ◽  
Roger Seei
Keyword(s):  
Spray Angle ◽  
Angle Measurements ◽  
Mechanical Methods

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.

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.

Impact of alternative fuel rheology on spraying process of small pressure-swirl atomizer

2016 ◽  
Author(s):  
Milan Malý ◽  
Lada Janáčková ◽  
Jan Jedelský ◽  
Miroslav Jícha
Keyword(s):  
Alternative Fuel ◽  
Small Pressure ◽  
Swirl Atomizer ◽  
Pressure Swirl ◽  
Spraying Process ◽  
Pressure Swirl Atomizer

scholarly journals The Two-Phase Conical Swirl Atomizers: Spray Characteristics

Energies ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3416 ◽  
Author(s):  
Marek Ochowiak ◽  
Andżelika Krupińska ◽  
Sylwia Włodarczak ◽  
Magdalena Matuszak ◽  
Małgorzata Markowska ◽  
...  
Keyword(s):  
Flow Rate ◽  
Discharge Coefficient ◽  
Experimental Studies ◽  
Central Area ◽  
Spray Angle ◽  
Sauter Mean Diameter ◽  
Spray Characteristics ◽  
Two Phase ◽  
Mean Diameter ◽  
The Impact

This paper presents the results of experimental studies on two-phase conical swirl atomizers. The impact of various atomizer geometries and different operational parameters of the atomization process on the spray characteristics was investigated. The influence of the mixing chamber height HS to diameter DS ratio and the volumetric flow rates of liquid and gas on the discharge coefficient values, spray angle, droplet size expressed by Sauter mean diameter D32, volumetric and radial distributions of droplet diameters in the spray stream were determined. The analysis of results showed that the discharge coefficient values depend on the Reynolds number for liquid and gas and the atomizer geometry. The spray angle increases as the flow rate of liquid and gas increases depending on the applied atomizer construction. The Sauter mean diameter value is correlated with the geometric dimensions of the atomizer swirl chamber. The rapid increase in D32 occurs after exceeding the value HS/DS ≈ 3. The Sauter mean diameter also depends on the operating parameters. A central area of stream is filled with smaller sized droplets as the gas flow rate increases.

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