scholarly journals Factors Affecting Spray Cone Angle of Pressure Swirl Atomizer for Gas Turbine Combustion Chamber: Theoretical and Experimental Analysis

2018 ◽  
Vol 11 (8) ◽  
pp. 1-4
Author(s):  
S. B. Dikshit ◽  
Digvijay Kulshreshta ◽  
S.A. Channiwala ◽  
◽  
◽  
...  
Keyword(s):  
Combustion Chamber ◽  
Gas Turbine ◽  
Experimental Analysis ◽  
Cone Angle ◽  
Spray Cone Angle ◽  
Spray Cone ◽  
Factors Affecting ◽  
Swirl Atomizer ◽  
Pressure Swirl ◽  
Pressure Swirl Atomizer

Numerical Analysis of Pressure Swirl Atomizer

2015 ◽  
Vol 798 ◽  
pp. 190-194
Author(s):  
Mehmet Kahraman ◽  
Guven Komurgoz ◽  
Ibrahim Ozkol
Keyword(s):  
Cone Angle ◽  
Computational Cost ◽  
Internal Flow ◽  
Combustion Engines ◽  
Spray Cone Angle ◽  
Spray Cone ◽  
Swirl Atomizer ◽  
Pressure Swirl ◽  
Pressure Swirl Atomizer

Atomization quality of liquids has a great importance on the performance of combustion engines. In this study the internal flow phenome of pressure swirl atomizer is investigated by using numerical method. The design of swirl atomizer is performed based on the requested atomizer characteristics which are sauter mean diamer (SMD), spray cone angle and break up length. Prediction and understanding of liquid film dynamics in the atomizer inside are the fundamental ways to explore atomizer performance. The purpose of this study is to estimate the air core size and film thickness in pressure swirl atomizer by setting single phase numeric computations. This article concludes that the CFD validated swirl atomizer design can be achieved with the lower computational cost using stream function methodology.

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.

Effect of Liquid/Gas Density Ratio on Primary Jet Breakup of Pressure Swirl Atomizer: Experimental and Numerical Study

2019 ◽  
Author(s):  
Edin Michael ◽  
Santhosh Kumar Keerthi ◽  
Krishna Kant ◽  
Pankaj Kolhe ◽  
Raja Banerjee ◽  
...  
Keyword(s):  
Numerical Study ◽  
Cone Angle ◽  
Density Ratio ◽  
Spray Cone Angle ◽  
Spray Cone ◽  
Gas Density ◽  
Jet Breakup ◽  
Swirl Atomizer ◽  
Pressure Swirl ◽  
Pressure Swirl Atomizer

Abstract This work reports experimental and numerical study of primary jet breakup of a pressure swirl atomizer. Experiments were performed in a constant volume spray chamber and the spray pattern was characterized as a function of different liquid/gas density ratios which was achieved by changing the ambient pressure. The liquid/gas density ratio was varied between ≈ 102 to 103 and the axial Reynold number was maintained at 6 × 103. Diffused backlight imaging in conjunction with high speed videography was used to visualize the spray. Parameters like spray cone angle, spray breakup length and flapping frequency was estimated. Additionally, POD analysis was performed to find the sheet instability modes. A corresponding numerical study using Coupled Level Set VOF method was performed keeping the liquid/gas density ratio of 10 and 102 to simulate the primary jet breakup using an in-house two-phase solver developed using OpenFOAM libraries. The solver was validated by following the numerical work of Fuster et al. Effect of computational mesh size on parameters like spray cone angle, breakup length was estimated.

Experimental Investigations of Performance Parameters of Pressure Swirl Atomizer for Kerosene Type Fuel

2009 ◽  
Author(s):  
Saurabh Dikshit ◽  
Salim Channiwala ◽  
Digvijay Kulshreshtha ◽  
Kamlesh Chaudhari
Keyword(s):  
Drop Size ◽  
Mechanical Energy ◽  
Cone Angle ◽  
Experimental Investigations ◽  
Performance Parameters ◽  
Spray Cone ◽  
Spray Penetration ◽  
Swirl Atomizer ◽  
Pressure Swirl ◽  
Pressure Swirl Atomizer

The process of atomization is one in which a liquid jet or sheet is disintegrated by the kinetic energy of the liquid itself, or by exposure to high velocity air or gas, or as a result of mechanical energy applied externally. Combustion of liquid fuels in engines and industrial furnaces is dependent on effective atomization to increase the specific surface area of the fuel and thereby achieve high rate of mixing and evaporation. The pressure swirl atomizer is most common type atomizer used for combustion in gas turbine engines and industrial furnaces. The spray penetration is of prime importance for combustion designs. Over penetration of the spray leads to impingement of the fuel on walls of furnaces and combustors. On the other hand, if spray penetration is inadequate, fuel–air mixing is unsatisfactory. Optimum engine performance is obtained when the spray penetration is matched to the size and geometry of combustors. Methods for calculating penetration are therefore essential to sound engine design. Equally important are the spray cone angles and the drop size distribution in the sprays. An attempt is being made to experimentally investigate pressure swirl atomizer performance parameters such as spray cone angle, penetration length and drop size at different injection pressures ranging from 6 bar to 18 bar.

Influence of Ambient Air Pressure on Pressure-Swirl Atomizer Spray Characteristics

2001 ◽  
Author(s):  
Arvind K. Jasuja ◽  
Arthur H. Lefebvre
Keyword(s):  
Gas Turbines ◽  
Drop Size ◽  
Cone Angle ◽  
Ambient Air ◽  
Air Pressure ◽  
Spray Characteristics ◽  
Spray Cone ◽  
Swirl Atomizer ◽  
Pressure Swirl ◽  
Pressure Swirl Atomizer

A single-component PDPA is used to evaluate the spray characteristics of a simplex pressure-swirl atomizer when operating at high liquid flow rates and elevated ambient air pressures. Attention is focused on the effects of air pressure on mean drop size, drop-size distribution, mean velocity, volume flux, and number density. Using a constant flow rate of 75 g/s, measurements are carried out along the spray radii at a fixed distance downstream from the atomizer face of 50 mm. The air pressures of 1, 8, and 12 bars chosen for these tests correspond to air densities of 1.2, 9.6, and 14.4 kg/m3. The purpose of the investigation is to supplement the existing body of information on pressure-swirl spray characteristics, most of which were obtained at normal atmospheric ambient pressures, with new data that correspond more closely to the conditions prevailing in the primary combustion zones of modern gas turbines. The results obtained are explained mainly in terms of the influence of air pressure on spray structure, in particular spray cone angle and Weber number.

Experimental and Numerical Studies of Diesel Spray Evaporation and Combustion in a Gas Turbine Matrix Burner

2009 ◽  
Author(s):  
Dieter Bohn ◽  
James F. Willie ◽  
Nils Ohlendorf
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Combustion Instability ◽  
Cone Angle ◽  
Spray Angle ◽  
Test Rig ◽  
Spray Cone Angle ◽  
Spray Cone ◽  
Flow Simulations ◽  
Air Inlet

Lean gas turbine combustion instability and control is currently a subject of interest for many researchers. The motivation for running gas turbines lean is to reduce NOx emissions. For this reason gas turbine combustors are being design using the Lean Premixed Prevaporized (LPP) concept. In this concept, the liquid fuel must first be atomized, vaporized and thoroughly premixed with the oxidizer before it enters the combustion chamber. One problem that is associated with running gas turbines lean and premixed is that they are prone to combustion instability. The matrix burner test rig at the Institute of Steam and Gas Turbines at the RWTH Aachen University is no exception. This matrix burner is suitable for simulating the conditions prevailing in stationary gas turbines. Till now this burner could handle only gaseous fuel injection. It is important for gas turbines in operation to be able to handle both gaseous and liquid fuels though. This paper reports the modification of this test rig in order for it to be able to handle both gaseous and liquid primary fuels. Many design issues like the number and position of injectors, the spray angle, nozzle type, droplet size distribution, etc. were considered. Starting with the determination of the spray cone angle from measurements, CFD was used in the initial design to determine the optimum position and number of injectors from cold flow simulations. This was followed by hot flow simulations to determine the dynamic behavior of the flame first without any forcing at the air inlet and with forcing at the air inlet. The effect of the forcing on the atomization is determined and discussed.

Effects of Fuel Nozzle Condition on Gas Turbine Combustion Chamber Exit Temperature Distributions

2010 ◽  
Author(s):  
Kristen Bishop ◽  
William Allan
Keyword(s):  
Combustion Chamber ◽  
Ambient Pressure ◽  
Cone Angle ◽  
Operating Conditions ◽  
Spray Cone Angle ◽  
Mixing Processes ◽  
Spray Cone ◽  
Temperature Distributions ◽  
Fuel Nozzle ◽  
Exit Temperature

The effects of fuel nozzle condition on the temperature distributions experienced by the nozzle guide vanes have been investigated using an optical patternator. Average spray cone angle, symmetry, and fuel streaks were quantified. An ambient pressure and temperature combustion chamber test rig was used to capture exit temperature distributions and to determine the pattern factor. The rig tests matched representative engine operating conditions by matching Mach number, equivalence ratio, and fuel droplet size. It was observed that very small deviations (± 10° in spray cone angle) from a nominal distribution in the fuel nozzle spray pattern correlated to increases in pattern factor, apparently due to a degradation of mixing processes, which created larger regions of very high temperature core flow and smaller regions of cooler temperatures within the combustion chamber exit plane. The spray cone angle had the most measureable influence while the effects of spray roundness and streak intensity had slightly less influence. Comparisons were made with published studies conducted on the combustion chamber geometry, and recommendations were made for fuel nozzle inspections.

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.

scholarly journals Dynamic Response of Fuel Nozzles for Liquid-Fueled Gas Turbine Combustors

1996 ◽  
Author(s):  
Mounir Ibrahim ◽  
Terry Sanders ◽  
Douglas Darling ◽  
Michelle Zaller
Keyword(s):  
Gas Turbine ◽  
Cone Angle ◽  
Outer Region ◽  
Test Fluid ◽  
Mean Flow ◽  
Spray Cone Angle ◽  
Spray Cone ◽  
Gas Turbine Combustors ◽  
The Mean ◽  
Piezoelectric Drive

To imitate resonances that might occur in the fuel delivery system of gas turbine combustors, the incoming liquid streams of two pressure swirl nozzles were perturbed using a piezoelectric driver. Frequencies of perturbations examined were from 3 to 20 kHz, and water was used as the test fluid. A video camera and a Phase Doppler Particle Analyzer (PDPA) were used to study the effect of perturbations on the mean flow quantities of the sprays. Various lighting arrangements were used for the video photography: back lighting, front lighting, a strobe synchronized with the input to the piezoelectric, and a laser sheet oriented along the midplane of the sprays. The study showed that the piezoelectric drive had an effect an the spray system at discrete frequencies. At these particular frequencies, by increasing the input voltage, it was found that the piezoelectric drive affected the atomization in the following ways: (1) the mean flow rate decreased, (2) the spray cone angle decreased, (3) the break up length decreased, (4) the peak of the spatial distribution of the mean droplet size decreased, and (5) the mean droplet sizes and velocities increased near the spray center line and decreased in the outer region of the spray. A hysteresis effect of the drive frequency on the spray cone angle was observed. The results indicated that more fundamental research is needed to gain an in-depth understanding of the physical processes induced in the spray by the piezoelectric drive.

scholarly journals Calculation of flow characteristics of liquid fuel supplied through pressure jet atomizers of small-sized gas turbine engines

2021 ◽  
Vol 20 (2) ◽  
pp. 19-35
Author(s):  
N. I. Gurakov ◽  
I. A. Zubrilin ◽  
M. Hernandez Morales ◽  
D. V. Yakushkin ◽  
A. A. Didenko ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Liquid Fuel ◽  
Cone Angle ◽  
Flow Characteristics ◽  
Design Parameters ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Spray Cone Angle ◽  
Spray Cone ◽  
Semi Empirical

The paper presents the results of studying the flow characteristics of liquid fuel in pressure jet atomizers of small-sized gas turbine engines with nozzle diameters of 0.4-0.6 mm for various operating and design parameters. The study was carried out using experimental measurements, semi-empirical correlations and CFD (computational fluid dynamics) methods. The Euler approach, the volume- of- fluid (VOF) method, was used to model multiphase flows in CFD simulations. Good agreement was obtained between experimental and predicted data on the fuel coefficient and the primary spray cone angle at the nozzle outlet. Besides, the assessment of the applicability of semi-empirical techniques for the nozzle configurations under consideration is given. In the future, the flow characteristics in question (the nozzle flow rate, the fuel film thickness, and the primary spray cone angle) can be used to determine the mean diameter of the droplets (SMD) required to fully determine the boundary conditions of fuel injection when modeling combustion processes in combustion chambers of small-sized gas turbine engines.

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