scholarly journals Atomization and combustion characteristics of a fuel–water rapid internal mixing injector

2019 ◽  
Author(s):  
Aizam Shahroni Mohd Arshad
Keyword(s):  
Water Content ◽  
Fuel Injection ◽  
Fuel Vapor ◽  
Sauter Mean Diameter ◽  
Liquid Ratio ◽  
Emulsified Fuel ◽  
Content Ratio ◽  
Internal Mixing ◽  
Mean Diameter ◽  
Atomization Characteristics

In this study, we investigated the atomization characteristics of rapid internal mixing injector (RIM injector) developed in our laboratory. RIM injector successfully emulsifies base fuel without any surfactant just before fuel injection. The diameter of droplet discharged from RIM injector was evaluated based on processing of shadowgraph images. It was found that Sauter mean diameter (SMD) of droplet is determined by the gas to liquid ratio (GLR) and viscosity of emulsified fuel. The increasing GLR decreases SMD value. As water content ratio is increased, the inner structure of droplet changes to W/O type emulsion. The emulsification increases its viscosity, which deteriorates the atomization characteristics. We proposed an empirical formula as functions of GLR and Reynolds number reproducing the deterioration resulting from increasing viscosity. The formula successfully predicts the SMD variation with respect to GLR and water content ratio. Finally, we examined the effect of atomization air ratio on NOx and PM emissions. The quantity of atomization air significantly influences the PM emission because the increasing air improves the mixing of fuel vapor with combustion air.

Drop Size Measurements in Evaporating Realistic Sprays of Emulsified and Neat Fuels

1983 ◽  
Author(s):  
Lee G. Dodge ◽  
Clifford A. Moses
Keyword(s):  
Drop Size ◽  
Elevated Temperatures ◽  
Jet Fuel ◽  
Sauter Mean Diameter ◽  
Emulsified Fuel ◽  
Fuel Jet ◽  
Mean Diameter ◽  
Detailed Computer ◽  
Particle Sizer ◽  
Additional Point

A comparative study has been performed of the drop-size distribution of sprays of emulsified and neat distillate-type aviation fuels at elevated temperatures (308K to 700K) and pressures (101 kPa to 586 kPa). All drop-size data were obtained with a Malvern Model 2200 Particle Sizer based on the forward angle diffraction pattern produced by the drops when illuminated by a collimated HeNe laser beam. Fuels included a standard multicomponent jet fuel, Jet-A, and a single component fuel, hexadecane, in both neat form and emulsified with 20 percent (by vol.) water and 2 percent (by vol.) surfactant. The initial breakup and atomization of a neat and emulsified fuel were quite similar at all conditions, and the evaporation rates appeared similar at various temperatures for pressures at or below about 300 kPa. At higher pressures with elevated temperatures the emulsified fuels of both types produce drops of significantly smaller Sauter mean diameter than the neat fuels as distance from the nozzle increases. These results are consistent with the microexplosion hypothesis, but there could also be alternative explanations. A detailed computer model which predicts heat up rates, steady state drop temperatures, evaporation rates, and drop trajectories has been used to help interpret the results. An additional point which has been observed is that the initial Sauter mean diameter produced with constant differential nozzle pressure is dependent on the air pressure with an exponent of about −0.4, i.e., SMD ∼ Pair−0.4. Some recent correlations often quoted omit the pressure (density) of air term.

scholarly journals Spray and atomization characteristics of gas-centered swirl coaxial injectors

2016 ◽  
Vol 9 (2) ◽  
pp. 127-140 ◽  
Author(s):  
Rahul Anand ◽  
PR Ajayalal ◽  
Vikash Kumar ◽  
A Salih ◽  
K Nandakumar
Keyword(s):  
Rocket Engine ◽  
Cone Angle ◽  
Spray Angle ◽  
Rocket Engines ◽  
Sauter Mean Diameter ◽  
Swirl Number ◽  
Spray Cone ◽  
Mean Diameter ◽  
Atomization Characteristics ◽  
Coaxial Injector

To achieve uniform and efficient combustion in a rocket engine, a fine uniform spray is needed. The same is achieved by designing an injector with good atomization characteristics. Gas-centered swirl coaxial (GCSC) injector elements have been preferred recently in liquid rocket engines because of an inherent capability to dampen the pressure oscillations in the thrust chamber. The gas-centered swirl coaxial injector chosen for this study is proposed to be used in a semi-cryogenic rocket engine operating with oxidizer rich hot exhaust gases from the pre-burner and liquid kerosene as fuel. In this paper, nine different configurations of gas-centered swirl coaxial injector, sorted out by studying the spray angle and coefficient of discharge with swirl number varying from 9 to 20 and recess ratio of 0.5, 1, and 1.5 are investigated for their atomization characteristics. Spray uniformity, spray cone angle, and droplet size in terms of Sauter mean diameter and mass median diameter are studied at various momentum flux ratios for all configurations. Sauter mean diameter is almost independent of recess ratio, whereas cone angle was inversely proportional to the recess ratio. A finer atomization was observed for injectors of high swirl number but the pressure drop also increased to achieve the same flow rate. An injector of medium swirl number and recess ratio of 1.5 is deemed most fit for above-mentioned application.

scholarly journals Experimental Study of the Effect of Dense Spray on Drop Size Measurement by Light Scattering Technology

1990 ◽  
Author(s):  
Ju Shan Chin ◽  
Wei Ming Li ◽  
Yan Zhang
Keyword(s):  
Experimental Data ◽  
Light Scattering ◽  
Correction Factor ◽  
Drop Size ◽  
Empirical Equation ◽  
Size Measurement ◽  
Sauter Mean Diameter ◽  
Internal Mixing ◽  
Mean Diameter ◽  
Factor Data

The effect of dense spray on drop size measurement by light scattering technology was studied by using Malvern instrument with five duplicated internal mixing airblast atomizers aligned in line with laser beam. The correction factor data for multiple scattering were obtained. By regression analysis, an empirical equation was obtained which correlated the correction factor as a function of obscuration (OBS), Sauter mean diameter under dilute spray condition SMD0. and drop size distribution parameter for Rosin–Rammler distribution under dilute spray conditions N0. The experimental data showed definitely that the correction factor is not only a function of OBS, SMD0, as proposed by Dodge, but also is a function of N0. The correlation fits the experimental data very well, and can be used for practical purposes to correct the data from Malvern drop sizer at high obscuration conditions.

scholarly journals Evaluation of Atomization Characteristics of Second Generation Biodiesel Using Air Blast Atomizer

2018 ◽  
Vol 7 (4.35) ◽  
pp. 772
Author(s):  
Gopinathan Muthaiyah ◽  
Kumaran Palanisamy
Keyword(s):  
Gas Turbine ◽  
Second Generation ◽  
High Viscosity ◽  
Spray Angle ◽  
Biodiesel Fuel ◽  
Sauter Mean Diameter ◽  
Evaporation Time ◽  
Air Blast ◽  
Mean Diameter ◽  
Atomization Characteristics

Biodiesel is one of the well-known renewable fuels that can be produced from organic oils and animal fats. Biodiesel fuel that meets ASTM D6751 fuel standards can replace diesel for reciprocating engine. On the other hand, biodiesel can also be considered for gas turbine application in power generation. Nevertheless, inferior properties of biodiesel such as high viscosity, density and surface tension results in inferior atomization and high emission which consequently hinders the fuel for gas turbine utilisation and generate higher emission pollutants. Therefore, this work focused on the evaluation of atomization characteristics of second generation biodiesel which is produced using microwave assisted post treatment scheme. The atomisation characteristics of second generation biodiesel was evaluated using air blast atomiser in terms of spray angle and spray length. Subsequently, numerical evaluation was performed to evaluate sauter mean diameter and droplet evaporation time of second generation biodiesel.  The results show, atomization characteristics of second generation biodiesel has improved in terms of spray angle and spray length, sauter mean diameter and shorter evaporation time compared to biodiesel which is commonly referred to as first generation biodiesel and fossil diesel.

scholarly journals Effect of the two-phase hybrid mode of effervescent atomizer on the atomization characteristics

Open Physics ◽  
2019 ◽  
Vol 17 (1) ◽  
pp. 960-965
Author(s):  
Liansheng Liu ◽  
Na Pei ◽  
Ruolin Zhao ◽  
Liang Tian ◽  
Runze Duan ◽  
...  
Keyword(s):  
Cone Angle ◽  
Great Influence ◽  
Design Parameters ◽  
Sauter Mean Diameter ◽  
Hybrid Mode ◽  
Two Phase ◽  
Mean Diameter ◽  
Effervescent Atomizer ◽  
Atomization Characteristics ◽  
Swirl Atomizer

Abstract In this paper, the atomization characteristics of an effervescent atomizer were investigated. The velocity, Sauter Mean Diameter (SMD) and atomization cone angle of the droplets were measured using the Phase Doppler Analyzer (PDA) to discuss the effect of different design parameters. The results showed that the atomization was unstable at a small Gas-Liquid Rate (GLR) while the atomization proved gradually by increasing the GLR. The optimal atomization region was at a GLR=0.1. In the atomization process, there existed a typical velocity distribution for the swirl atomizer. The design parameters of atomizer provided a great influence on the Sauter Mean Diameter (SMD) and atomization cone angle. The experiment results showed that some droplets had negative velocities.

Experimental Study of the Effect of Dense Spray on Drop Size Measurement by Light Scattering Technology

1992 ◽  
Vol 114 (1) ◽  
pp. 82-88 ◽  
Author(s):  
Ju Shan Chin ◽  
Wei Ming Li ◽  
Yan Zhang
Keyword(s):  
Experimental Data ◽  
Light Scattering ◽  
Correction Factor ◽  
Drop Size ◽  
Empirical Equation ◽  
Size Measurement ◽  
Sauter Mean Diameter ◽  
Internal Mixing ◽  
Mean Diameter ◽  
Factor Data

The effect of dense spray on drop size measurement by light scattering technology was studied using a Malvern instrument with five duplicated internal mixing airblast atomizers aligned with a laser beam. The correction factor data for multiple scattering were obtained. By regression analysis, an empirical equation was obtained that correlated the correction factor as a function of obscuration (OBS), Sauter mean diameter under dilute spray condition (SMD0), and drop size distribution parameter for Rosin-Rammler distribution under dilute spray conditions (N0). The experimental data showed definitely that the correction factor is not only a function of OBS and SMD0, as proposed by Dodge, but also is a function of N0. The correlation fits the experimental data very well, and can be used for practical purposes to correct the data from the Malvern drop sizer at high obscuration conditions.

scholarly journals Influence of Water Content Ratio on Combustion Fluctuation of Diesel Engine Using Emulsified Fuel

1997 ◽  
Vol 32 (6) ◽  
pp. 433-440
Author(s):  
Yasufumi Yoshimoto ◽  
Toshinori Kuramoto ◽  
Ziye Li ◽  
Minoru Tsukahara
Keyword(s):  
Diesel Engine ◽  
Water Content ◽  
Emulsified Fuel ◽  
Content Ratio ◽  
Influence Of Water

Experiment Study and Simulation Research for the Atomization Characteristics of the Internal-Mixing Twin-Fluid Atomizer

2014 ◽  
Vol 1049-1050 ◽  
pp. 1075-1082
Author(s):  
Peng Bo Bai ◽  
Yu Ming Xing ◽  
Ze Wang
Keyword(s):  
Droplet Size ◽  
Three Dimensional ◽  
Operating Conditions ◽  
Air Pressure ◽  
Experimental Result ◽  
Hydraulic Pressure ◽  
Liquid Ratio ◽  
Energy Field ◽  
Internal Mixing ◽  
Atomization Characteristics

The internal-mixing twin-fluid atomizer has found wide application in aerospace, industrial gas turbine, oil-fired boiler, energy field and so on. The atomization characteristics of internal mixing nozzle under different operating conditions are studied by utilizing the Malvern laser particle size analyzer. According to the experiment results, the influence of air pressure, hydraulic pressure and air-liquid ratio to droplet size and uniformity are analyzed. The three-dimensional flow field model of internal mixing nozzle is built to simulate the droplet size of mixing room and outlet by Fluent. The simulation results show that the droplet size decreases along with the increase of the air pressure and the air-liquid ratio, moreover, the air pressure plays a main actor. The droplet size increases in the mixing room, and then decrease sharply at the domain of the outlet. The droplet size of the nozzle’s outlet obtained in simulation matches the experimental result.

scholarly journals Rapid emulsification of a fuel–water rapid internal mixing injector for emulsion fuel combustion

2018 ◽  
Author(s):  
Aizam Shahroni Mohd Arshad ◽  
Yuzuru Nada ◽  
Yoshiyuki Kidoguchi ◽  
Daisuke Asao
Keyword(s):  
Water Content ◽  
Fuel Mixture ◽  
High Viscosity ◽  
Oil Emulsion ◽  
Content Ratio ◽  
Internal Mixing ◽  
Wide Range ◽  
Particulate Matter Emissions ◽  
Additional Processing ◽  
Water In Oil Emulsion

In this study, a fuel–water rapid internal mixing injector capable of reducing emissions from combustion furnaces operating under high load conditions was developed. Employing this injector allows the injection of a fresh emulsified fuel mixture without requiring surfactants or additional processing equipment. The aim of the present study was to investigate the emulsification, atomization, and emission performance of the injector when using soybean oil as a model high-viscosity fuel from a renewable source. Successful emulsification was observed in the mixing chamber over a wide range of water content ratios up to 0.5, under which a water-in-oil emulsion was discharged from the injector. As the water content ratio was increased, the Sauter mean diameter of the droplets in the spray increased. This is a result of the decrease in the mass flow ratio of atomizing gas to liquid and the increase in the viscosity of the fuel emulsion. Although the emulsification of the base fuel resulted in the discharge of large droplets, the results showed that the nitrogen oxide and particulate matter emissions from a combustion furnace incorporating the injector were found to be reduced simultaneously following the introduction of water even under a high combustion load.

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