Effect of application of electric force to diesel fuel droplets charged through Millikan oil-drop experiment on physical and thermal characteristics of flame

2021 ◽  
pp. 1-15
Author(s):  
S.H. Poorhoseini ◽  
H. Ramezani-Aval
Keyword(s):  
Diesel Fuel ◽  
Liquid Fuel ◽  
Cone Angle ◽  
Flame Temperature ◽  
Thermal Characteristics ◽  
Electric Force ◽  
Continuous Change ◽  
Mixing Rate ◽  
Spray Cone ◽  
Fuel Droplets

Abstract This paper proposes a new feasible method to allow continuous change in the primary injection spray cone angle of liquid fuel droplets, which are injected from nozzles in liquid fuel combustion systems, to control the flame shape and thermal characteristics of the flame. The method is based on electric force applied to fuel droplets charged through frictional effects between the internal surface of the nozzle and the fuel flow as the liquid fuel is sprayed (based on the Millikan oil-drop experiment). A sprint computational fluid dynamics (CFD) code was developed to investigate the effect of application of electric force to charged diesel fuel droplets, which were injected from a pressure swirl atomizer, on physical and thermal characteristics of a two-dimensional axisymmetric turbulent jet diffusion flame. The results show that an electric field applied to charged fuel droplets (electric force) changes the spatial distribution of the liquid fuel droplets in the flame reaction zone. An applied electric force in (−y) direction diverts the fuel droplets towards the axis centerline of the furnace and, consequently, decreases the primary injection cone angle and increases the concentration of the evaporated droplets around the axis centerline, which enhances the fuel-oxidant mixing rate and raises the flame temperature. Unlike an applied electric force in (−y) direction, an applied electric force in (+y) direction decreases the flame temperature. However, as the primary injection cone angle is decreased, an applied electric force in (+y) direction increases the flame temperature.

scholarly journals Experimental study on the effect of spray cone angle on the characteristics of horizontal jet spray flame under sub-atmospheric pressure

2020 ◽  
Vol 24 (5 Part A) ◽  
pp. 2941-2952 ◽  
Author(s):  
Kai Xie ◽  
Xingqi Qiu ◽  
Yunjing Cui ◽  
Jianxin Wang
Keyword(s):  
Atmospheric Pressure ◽  
Cone Angle ◽  
Flame Temperature ◽  
Normal Pressure ◽  
Low Pressure ◽  
Dimensionless Temperature ◽  
Thermal Imager ◽  
Spray Cone Angle ◽  
Spray Cone ◽  
Matlab Programming

The burning state of a plateau environment is attracting more and more attention. In this paper, in order to have a deeper scientific understanding of diesel spray combustion and the characteristics of a flame under different spray cone angles in a plateau environment, experiments were carried out in a low pressure chamber. The flame morphology was recorded by a high speed video instrument, and the temperature change was recorded by a thermal imager and thermocouples. The MATLAB programming was used to process the video image of the flame, and the probability of its binarization was calculated. The results indicate that the flame becomes longer and wider under different pressures with the same spray angle. The variation is more pronounced at a smaller spray taper angle. The flame uplifted height characteristic is mainly negatively related to the atmospheric pressure. According to the normalized flame temperature and the dimensionless horizontal projection, the length can be divided into three regions. In the region of buoyancy flame, the dimensionless temperature varies with sub-atmospheric pressure more than with normal pressure. In addition, under different spray cone angle conditions, the law of variation in the normalized flame temperature under sub-atmospheric pressure is exactly opposite to that under normal pressure. This study is of great significance to the scientific research on flames in a low pressure environment, and the design of different fuel nozzles for application in a plateau environment.

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.

Characterizing Diesel Fuel Spray Cone Angle From Back-Scattered Imaging by Fitting Gaussian Profiles to Radial Spray Intensity Distributions

2012 ◽  
Vol 134 (6) ◽  
Author(s):  
Jaclyn E. Johnson ◽  
Jeffrey D. Naber ◽  
Seong-Young Lee
Keyword(s):  
Charge Density ◽  
Diesel Fuel ◽  
Curve Fitting ◽  
Cone Angle ◽  
Injection Pressure ◽  
Fuel Spray ◽  
Spray Cone Angle ◽  
Spray Cone ◽  
Gaussian Curve

Quantifying fuel spray properties including penetration, cone angle, and vaporization processes sheds light on fuel-air mixing phenomenon, which governs subsequent combustion and emissions formation in diesel engines. Accurate experimental determination of these spray properties is a challenge but imperative to validate computational fluid dynamic (CFD) models for combustion prediction. This study proposes a new threshold independent method for determination of spray cone angle when using Mie back-scattering optical diagnostics to visualize diesel sprays in an optically accessible constant volume vessel. Test conditions include the influence of charge density (17.6 and 34.9 kg/m3) at 1990 bar injection pressure, and the influence of injection pressure (990, 1370, and 1980 bar) at a charge density of 34.8 kg/m3 on diesel fuel spray formation from a multi-hole injector into nitrogen at a temperature of 100 °C. Conventional thresholding to convert an image to black and white for processing and determination of cone angle is threshold subjective. As an alternative, an image processing method was developed, which fits a Gaussian curve to the intensity distribution of the spray at radial spray cross-sections and uses the resulting parameters to define the spray edge and hence cone angle. This Gaussian curve fitting methodology is shown to provide a robust method for cone angle determination, accounting for reductions in intensity at the radial spray edge. Results are presented for non-vaporizing sprays using this Gaussian curve fitting method and compared to the conventional thresholding based method.

Effect of Injection Parameters on the Spray Characteristics of DME Fuel

2006 ◽  
Author(s):  
Bong Woo Ryu ◽  
Seung Hwan Bang ◽  
Hyun Kyu Suh ◽  
Chang Sik Lee
Keyword(s):  
Dimethyl Ether ◽  
Diesel Fuel ◽  
Cone Angle ◽  
Injection Pressure ◽  
Injection Rate ◽  
Spray Characteristics ◽  
Spray Cone Angle ◽  
Spray Cone ◽  
Injection Duration ◽  
Injection Parameters

The purpose of this study is to investigate the effect of injection parameters on the injection and spray characteristics of dimethyl ether and diesel fuel. In order to analyze the injection and spray characteristics of dimethyl ether and diesel fuel with employing high-pressure common-rail injection system, the injection characteristics such as injection delay, injection duration, and injection rate, spray cone angle and spray tip penetration was investigated by using the injection rate measuring system and the spray visualization system. In this work, the experiments of injection rate and spray visualization are performed at various injection parameters. It was found that injection quantity was decreased with the increase of injection pressure at the same energizing duration and injection pressure In the case of injection characteristics, dimethyl ether showed shorter of injection delay, longer injection duration and lower injected mass flow rate than diesel fuel in accordance with various energizing durations and injection pressures. Also, spray development of dimethyl ether had larger spray cone angle than that of diesel fuel at various injection pressures. Spray tip penetration was almost same development and tendency regardless of injection angles.

scholarly journals Numerical study on flame and emission characteristics of a small flue gas self-circulation diesel burner with different spray cone angles

2021 ◽  
pp. 150-150
Author(s):  
Kai Xie ◽  
Jie Zhang ◽  
Changlin Qin ◽  
Xiufeng Tan ◽  
Yunjing Cui
Keyword(s):  
Flue Gas ◽  
Numerical Study ◽  
Cone Angle ◽  
Flame Temperature ◽  
Flame Length ◽  
Physical Aspect ◽  
Emission Characteristics ◽  
Spray Cone Angle ◽  
Spray Cone ◽  
Numerical Calculation Method

The problems of long flame and high pollution emissions in low-power burners are of wide concern in small heating devices. To solve this problem, a small diesel burner with self-circulation flue gas was designed herein. In order to obtain a deeper scientific understanding of the flame and emission characteristics of the burner with different spray cone angles, a numerical calculation method was used to investigate them. Reasonable flow, heat transfer, and combustion models were selected, and periodic boundary conditions were used to verify the feasibility of the numerical model. The results indicate that the flame length increases with increasing spray cone angle, and then the flame length basically stabilizes at 410 mm. The maximum flame temperature decreases slightly with increasing spray cone angle. Besides this, the NO emission of this small flue gas self-circulation burner decreases with increasing spray cone angle and is as low as 10 ppm at an 80? spray cone angle. In addition, the influence mechanism of the spray cone angle on the flue gas self-circulation ratio was analyzed from the physical aspect of the spray area and the chemical aspect of combustion. This study is of great significance to research on the flame morphology of small flue gas self-circulation burners and the selection of different spray cone angles.

SPRAY VISUALIZATION OF HYDROTREATED VEGETABLE OIL UNDER SIMULATED DIESEL ENGINE CONDITION

2020 ◽  
Vol 40 (04) ◽  
Author(s):  
VO TAN CHAU
Keyword(s):  
Vegetable Oil ◽  
Diesel Fuel ◽  
Alternative Fuels ◽  
Cone Angle ◽  
Injection Pressure ◽  
Fuel Properties ◽  
Spray Characteristics ◽  
Spray Cone Angle ◽  
Penetration Length ◽  
Spray Cone

The diversity of alternative fuels and the corresponding variation in their physical and chemical properties, coupled with simultaneous changes in advanced techniques for CI-engine, needed to improve engine efficiency and emissions. Hydrotreated Vegetable Oil (HVO), seen as a promising substitution for petrol-diesel, and diesel fuel (mixed of 7% palm-biodiesel or B7) were analyzed on fuel properties. Then, the influence of these fuel properties on spray characteristics in constant volume combustion chamber were evaluated under conditions of single hole injector of 200m diameter, injection pressure of 100MPa, constant back pressure of 4.0MPa and energizing time of 2.5ms. The results show that HVO had smaller in viscosity (18.48%), density (5.52%), sulfur content, distillation under T50, T90 and higher in derived cetane index (27.2%), heating value (2.2%), respectively, compared to diesel. Spray characteristics of HVO had the same propensity with diesel fuel. HVO revealed a slightly shorter in penetration length (5%) during fully developed zone, a larger spray cone angle (from 0.2 to 1.1 degree wider in quasi-steady state). Both fuels had a similar maximum spray velocity reaching at 5mm to 10mm from nozzle orifice. Also observed was an increase in spray volume of HVO.

Characterizing Diesel Fuel Spray Cone Angle From Back-Scattered Imaging by Fitting Gaussian Profiles to Radial Spray Intensity Distributions

2011 ◽  
Author(s):  
Jaclyn E. Nesbitt ◽  
Jeffrey D. Naber ◽  
Seong-Young Lee
Keyword(s):  
Charge Density ◽  
Diesel Fuel ◽  
Curve Fitting ◽  
Cone Angle ◽  
Injection Pressure ◽  
Fuel Spray ◽  
Spray Cone Angle ◽  
Spray Cone ◽  
Gaussian Curve

Quantifying fuel spray properties including penetration, cone angle, and vaporization processes sheds light on fuel-air mixing phenomenon which governs subsequent combustion and emissions formation in diesel engines. Accurate experimental determination of these spray properties is a challenge but imperative to validate computational fluid dynamic (CFD) models for combustion prediction. This study proposes a new threshold independent method for determination of spray cone angle when using Mie back-scattering optical diagnostics to visualize diesel sprays in an optically accessible constant volume vessel. Test conditions include the influence of charge density (17.6 and 34.9 kg/m3) at 1990 bar injection pressure, and the influence of injection pressure (990, 1370, and 1980 bar) at a charge density of 34.8 kg/m3 on diesel fuel spray formation from a multi-hole injector into nitrogen at a temperature of 100°C. Conventional thresholding to convert an image to black and white for processing and determination of cone angle is threshold subjective. As an alternative, an image processing method was developed which fits a Gaussian curve to the intensity distribution of the spray at radial spray cross-sections and uses the resulting parameters to define the spray edge and hence cone angle. This Gaussian curve fitting methodology is shown to provide a robust method for cone angle determination, accounting for reductions in intensity at the radial spray edge. Results are presented for non-vaporizing sprays using this Gaussian curve fitting method and compared to the conventional thresholding based method.

scholarly journals Ignition of liquid droplets fuels under conditions of radiation-conductive heating in air

2018 ◽  
Vol 194 ◽  
pp. 01062
Author(s):  
Arkadiy V. Zakharevich ◽  
Mikhail S. Zygin ◽  
Dmitriy N. Tsymbalov
Keyword(s):  
Experimental Investigation ◽  
Diesel Fuel ◽  
Ignition Delay ◽  
Delay Time ◽  
Liquid Fuel ◽  
Ignition Delay Time ◽  
Initial Temperature ◽  
Liquid Droplets ◽  
Conductive Heating ◽  
Fuel Droplets

The results of an experimental investigation of ignition liquid fuel (kerosene, diesel fuel) by the single drops under conditions of radiation-conducting heating in air are presented. The dependences of the ignition delay time of the typical fuels droplets on the initial temperature of the heated oxidant in a limited space are established. The parameters of stable ignition of liquid fuel droplets are set.

The Effects of Ester Structure on Transient Fuel Spray Characteristics Including Novel Image Analysis to Quantify Air Entrainment

2015 ◽  
Author(s):  
Luis G. Gutierrez ◽  
Mohammad Fatouraie ◽  
Steve B. Xiao ◽  
Margaret S. Wooldridge ◽  
Dong Han ◽  
...  
Keyword(s):  
Diesel Fuel ◽  
High Speed ◽  
Penetration Rate ◽  
Cone Angle ◽  
Air Entrainment ◽  
Fuel Injector ◽  
Spray Characteristics ◽  
Spray Cone ◽  
Penetration Distance ◽  
Injection Process

Achieving efficient and clean combustion of biodiesel as a renewable source of energy requires a fundamental understanding of the effects of the different thermophysical properties on the fuel injection process at conditions relevant to diesel engines. In this study, the spray characteristics of two fatty acid esters, methyl oleate and ethyl oleate, are compared to a baseline diesel fuel using high-speed imaging of the sprays in a constant volume chamber. A single hole fuel injector with a nozzle diameter of 280 μm was used with a single injection event with a duration of 1.0 ms. The spray development was investigated for fuel-rail pressures of 40, 60, 80 and 100 MPa and the chamber gas densities of 1.15 kg/m3, 5.75 kg/m3 and 11.5 kg/m3. High-speed shadowgraph imaging of the non-vaporizing sprays was performed at 15,000 frames per second. Image processing algorithms were developed to quantify the spray penetration distance, penetration rate and cone angle as a function of time for the injection process. Penetration distance and penetration rate results were similar for the esters and diesel fuel for the range of experimental conditions studied. However, diesel had a larger spray cone angle compared to both esters. Additionally a novel metric for air entrainment was developed based on the macro-scale features of the spray. The integrated mixing volume metric showed no difference in air entrainment between the fuels, which is in good agreement with the behavior expected based on spray theory.

Spray Characteristics of Diesel and Biodiesel Fuels for Various Injection Timings under Non Evaporating Conditions

2015 ◽  
Vol 787 ◽  
pp. 682-686 ◽  
Author(s):  
P. Raghu ◽  
N. Nallusamy ◽  
Pitchandi Kasivisvanathan
Keyword(s):  
Methyl Ester ◽  
Diesel Fuel ◽  
Alternative Fuels ◽  
Internal Combustion Engines ◽  
Cone Angle ◽  
Spray Characteristics ◽  
Spray Cone Angle ◽  
Spray Cone ◽  
Spray Tip Penetration ◽  
Biodiesel Fuels

Fuel spray and atomization characteristics play a vital role in the performance of internal combustion engines. Petroleum fuels are expected to be depleted within a few decades, finding alternative fuels that are economically viable to replace the petroleum fuel has attracted much research attention. In this work spray characteristics such as spray tip penetration, spray cone angle and spray area were investigated for Karanja oil methyl ester (KOME), Jatropha oil methyl ester (JOME) and diesel fuel. The KOME and JOME sprays were characterized and compared with diesel sprays at different injection timings. The macroscopic spray properties were acquired from the images captured by a high speed video camera employing shadowgraphic and image processing techniques in a spray chamber. The experimental results showed that biodiesel fuels had different features compared with diesel fuel after start of injection (ASOI). Longer spray tip penetration, larger spray area and smaller spray cone angle were observed for biodiesel (JOME, KOME) due to its higher density and viscosity than that of diesel fuel.

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