Measurements of n-Heptane Liquid Length and Spray Cone Angle for Low-Temperature, Low-Density Conditions in an Optically Accessible Flow Vessel

2014 ◽  
Author(s):  
Jin Wang ◽  
Kemar C. James ◽  
Michael C. Maynard ◽  
Brian T. Fisher
Keyword(s):  
Liquid Phase ◽  
Low Temperature ◽  
High Speed ◽  
Direct Injection ◽  
Cone Angle ◽  
Low Density ◽  
Low Temperature Combustion ◽  
Ambient Conditions ◽  
Spray Cone Angle ◽  
Spray Cone

The purpose of this study was to measure global properties of n-heptane sprays using high-speed spray visualization in a newly developed constant-pressure flow vessel. Liquid-phase fuel penetration distance and cone angle were determined for low-density and low-temperature ambient conditions, which are increasingly relevant due to the advent of early direct-injection low-temperature combustion. Results indicated that fuel sprays under these conditions do not behave as predicted by established models. Penetration distances increased steadily throughout and after injection, and liquid-phase fuel persisted long after end of injection. Results suggest that these sprays vaporize extremely slowly and could cause wall-wetting issues.

Development of a High-Pressure, High-Temperature, Optically Accessible Continuous-Flow Vessel for Fuel-Injection Experiments

2013 ◽  
Author(s):  
Kemar C. James ◽  
Jin Wang ◽  
Zackery B. Morris ◽  
Michael C. Maynard ◽  
Brian T. Fisher
Keyword(s):  
Liquid Phase ◽  
Continuous Flow ◽  
High Speed ◽  
Fuel Injection ◽  
Cone Angle ◽  
Injection Pressure ◽  
Spray Cone Angle ◽  
Spray Cone ◽  
Spray Visualization

The focus of this work was to develop a continuous-flow vessel with extensive optical access for characterization of engine-relevant fuel-injection and spray processes. The spray chamber was designed for non-reacting experiments at pressures up to 1380 kPa (200 psi) and temperatures up to 200°C. Continuous flow of inert “sweep gas” enables acquisition of large statistical data samples and thus potentially enables characterization of stochastic spray processes. A custom flange was designed to hold a common-rail diesel injector, with significant flexibility to accommodate other injectors and injector types in the future. This flexibility, combined with the continuous flow through the chamber, may enable studies of gas-turbine direct-injection spray processes in the future. Overall, the user can control and vary: injection duration, injection pressure, sweep-gas temperature, sweep-gas pressure, and sweep-gas flow rate. The user also can control frequency of replicate injections. There are four flat windows installed orthogonally on the vessel for optical access. Optical data, at present, include global spray properties such as liquid-phase fuel penetration and cone angle. These measurements are made using a high-speed spray-visualization system (up to 100 kHz) consisting of a fast-pulsed LED (light emitting diode) source and a high-speed camera. Experimental control and data acquisition have been set up and synchronized using custom LabVIEW programs. The culmination of this development effort was an initial demonstration experiment to capture high-speed spray-visualization movies of n-heptane injections to determine liquid-phase fuel penetration length (i.e., liquid length) and spray cone angle. In this initial experiment, fuel-injection pressure was ∼120 MPa (1200 bar) and the injection command-pulse duration was 800 μs. At room conditions, liquid length and nominal spray cone angle were ∼170 mm and ∼14.5°, respectively. In contrast, with air flow in the chamber at 100 psi and 100°C, liquid length was considerably shorter at ∼92 mm and spray cone angle was wider at ∼16.5°. Future experiments will include the continuation of these measurements for a wider range of conditions and fuels, extension of high-speed imaging to vapor-phase fuel penetration using schlieren imaging techniques, and detailed characterization of spray properties near the injector nozzle and near the liquid length.

Experimental Study on Diesel Engine and Analysis the Spray Characteristics of Diesel and Biodiesel by Varying Injection Pressure

2014 ◽  
Vol 984-985 ◽  
pp. 932-937 ◽  
Author(s):  
Palani Raghu ◽  
M. Senthamil Selvan ◽  
K. Pitchandi ◽  
N. Nallusamy
Keyword(s):  
Experimental Study ◽  
Diesel Engine ◽  
Weber Number ◽  
Direct Injection ◽  
Cone Angle ◽  
Injection Pressure ◽  
Injection Velocity ◽  
Spray Characteristics ◽  
Spray Cone Angle ◽  
Spray Cone

— The spray characteristic of the injected fuel is mainly depends upon fuel injection pressure, temperature, ambient pressure, fuel viscosity and fuel density. An experimental study was conducted to examine the effect of injection pressure on the spray was injected into direct injection (DI) diesel engine in the atmospheric condition. In Diesel engine, the window of 20 mm diameter hole and the transparent quartz glass materials were used for visualizing spray characteristics of combustion chamber at right angle triangle position. The varying Injection pressure of 180 - 240 bar and the engine was hand cranked for conducting the experiments. Spray characteristics for Jatropha oil methyl ester (JOME) and diesel were studied experimentally. Spray tip penetration and spray cone angle were measured in a combustion chamber of Direct Injection diesel engine by employing high speed Digital camera using Mie Scattering Technique and ImageJ software. The study shows the JOME gives longer spray tip penetration and smaller spray cone angle than those of diesel fuels. The Spray breakup region (Reynolds number, Weber number), Injection velocity and Sauter Mean Diameter (SMD) were determined for diesel and JOME. SMD decreases for JOME than diesel and the Injection velocity, Reynolds Number, Weber Number Increases for JOME than diesel.

Experimental Study on Spray Characteristics of Diesel Engines and Analysis of Fuel Dripping Phenomenon

2014 ◽  
Vol 1078 ◽  
pp. 271-275 ◽  
Author(s):  
Yu Qiang Wu ◽  
Qian Wang ◽  
Zhi Sheng Gao ◽  
Zhou Rong Zhang ◽  
Li Ming Dai
Keyword(s):  
Experimental Study ◽  
High Speed ◽  
Cone Angle ◽  
Digital Camera ◽  
Injection Pressure ◽  
Fuel Mixture ◽  
Long Distance ◽  
Spray Characteristics ◽  
Spray Cone Angle ◽  
Spray Cone

Experimental study on macroscopic spray characteristics of a certain type of domestic common rail injectors under the conditions of different injection pressures was carried out through a high-speed digital camera. Furthermore, a fuel dripping phenomenon at the end stage of injection was observed through the high-speed digital camera equipped with a long-distance microscope, and a further analysis of the phenomenon was made. The results show the increase in the injection pressure can evidently enhance spray cone angle and expand the scope of spray field in combustion chamber, which is conducive to air-fuel mixture. The spray cone angle during the development spray shows a double-peak shape. And the long response-time of seating of solenoid valve core that disables the injection cutting off in time is one of factors causing fuel dripping phenomenon.

Experimental investigations of kerosene sprays in pressurized evaporating environments

2018 ◽  
Vol 233 (3) ◽  
pp. 413-427 ◽  
Author(s):  
Tao Liu ◽  
Wei Fu ◽  
Bolun Yi ◽  
Lanbo Song ◽  
Qizhao Lin ◽  
...  
Keyword(s):  
Experimental Data ◽  
Ambient Temperature ◽  
High Speed ◽  
Ambient Pressure ◽  
Cone Angle ◽  
Experimental Investigations ◽  
Spray Cone Angle ◽  
Spray Cone ◽  
Ambient Temperatures ◽  
Performance And Emissions

Experiments of kerosene spray with single-hole solenoid injector in the pressurized nonevaporating and evaporating environments, in which the ambient pressure ranges from 1.4 MPa to 4.8 MPa and the ambient temperature includes 300 K, 343 K, and 423 K, are carried out with high-speed Schlieren photography to investigate the breakup regimes and the macro-characteristics like penetration, projected spray area, and spray cone angle. Repetitive experiments are conducted to analyze the penetration repeatability. The comparison between the experimental penetrations and the predicted ones by the existing correlations reveals that the deviations between the experimental data and the predictions rise as the ambient temperature rises. Therefore, a new modified correlation is proposed to predict the penetration of kerosene spray in the nonevaporating and evaporating environments, which fits the experimental data better than the existing correlations. The breakup regimes in primary breakup and secondary breakup are discussed respectively. The projected spray area is analyzed under different ambient pressures at different ambient temperatures. Finally, it is found that the spray cone angle remains almost the same under different ambient pressures after it reduces sharply before 0.5 ms. The macro-characteristics discussed in the present study are important for the performance and emissions of aeronautical engines or diesel engines fuelled by kerosene as a substitution.

Spray Performance of Alternative Jet Fuel Based Nanofuels at High-Ambient Conditions

2018 ◽  
Author(s):  
Mohamed Soltan ◽  
Buthaina Al Abdulla ◽  
AlReem Al Dosari ◽  
Kumaran Kannaiyan ◽  
Reza Sadr
Keyword(s):  
Ambient Pressure ◽  
Cone Angle ◽  
Jet Fuel ◽  
Liquid Sheet ◽  
Ambient Conditions ◽  
Spray Characteristics ◽  
Atomization Process ◽  
Spray Cone Angle ◽  
Spray Cone ◽  
Sheet Breakup

Dispersion of nanoparticles in pure fuels alters their key fuel physical properties, which could affect their atomization process, and in turn, their combustion and emission characteristics in a combustion chamber. Therefore, it is essential to have a thorough knowledge of the atomization characteristics of nanofuels (nanoparticles dispersed in pure fuels) to better understand their latter processes. This serves as the motivation for the present work, which attempts to gain a good understanding of the atomization process of the alternative, gas-to-liquid (GTL), jet fuel based nanofuels. The macroscopic spray characteristics such as spray cone angle, liquid sheet breakup, and liquid sheet velocity are determined by employing shadowgraph imaging technique. The effect of nanoparticles weight concentration and ambient pressures on the spray characteristics are investigated in a high pressure-high temperature constant volume spray rig. To this end, a pressure swirl nozzle with an exit diameter of 0.8 mm is used to atomize the fuels. The macroscopic spray results demonstrate that the nanoparticles dispersion at low concentrations affect the near nozzle region. The spray liquid sheet breakup distance is reduced by the presence of nanoparticle due to the early onset of disruption in the liquid sheet. Consequently, the liquid sheet velocity in that spray region is higher for nanofuels when compared to that of pure fuels. Also, the ambient pressure has a significant effect on the spray features as reported in the literature.

Numerical Analysis of Swirl Chamber Combustion System in DI Diesel Engines with the Conical-Spray

2015 ◽  
Vol 752-753 ◽  
pp. 922-927
Author(s):  
Sheng Li Wei ◽  
Kun Peng Ji ◽  
Xian Yin Leng ◽  
Xuan Liu
Keyword(s):  
Diesel Engines ◽  
Direct Injection ◽  
Cone Angle ◽  
Combustion System ◽  
Combustion Chambers ◽  
Spray Cone Angle ◽  
Spray Cone ◽  
Swirl Chamber ◽  
Narrow Passage ◽  
Combustion Processes

In order to promote the quality of mixture and improve the fuel spray spatial distribution, enhancing airflow movement in a combustion chamber, a new swirl chamber combustion system in DI (direct injection) diesel engines is proposed based on conical-spray. Numerical simulations have been conducted by using the FIRE v2008 code. Several different widths of passage and spray angles are investigated in a single cylinder 135 diesel engine. The combustion and emissions performance were investigated by different conical-spray nozzles and combustion chambers with a constant compression ratio. The results show that using this combustion system, the mixture formation and combustion processes have been improved by a certain longitudinal swirl when the air is squished into the swirl chamber through the relative narrow passage. Moreover, the formation of homogeneous mixture is accelerated and the combustion is improved compared with that of conventional combustion system. The cases show the passage width of 5mm and conical spray cone angle of 140° has a better performance in the new combustion system.

Experimental Study on Spray Characteristics of N-Butanol/Acidic Oil/Diesel Blends

2014 ◽  
Vol 1008-1009 ◽  
pp. 1001-1005 ◽  
Author(s):  
Jian Wu ◽  
Yang Hua ◽  
Zhan Cheng Wang ◽  
Li Li Zhu ◽  
Wei Wei Shang
Keyword(s):  
Experimental Study ◽  
High Speed ◽  
Cone Angle ◽  
Injection Pressure ◽  
Air Entrainment ◽  
Mixing Ratio ◽  
Spray Characteristics ◽  
Spray Cone Angle ◽  
Spray Cone ◽  
Spray Penetration

In order to better research on the spray characteristics of biodiesel and n-butanol blends, an experimental study of spray characteristics of different fuel mixtures was investigated in a constant volume vessel using high speed photograph method, and analyzed the influence of different proportions of acidic oil biodiesel and n-butanol on the macroscopic parameters of spray penetration, spray cone angle and so on. The results show that with the increase of acidic oil biodiesel ratio, the air entrainment is weakened, spray penetration gradually increases and spray cone angle decreases under the same injection pressure and back pressure. After adding n-butanol in acidic oil biodiesel and diesel mixture fuel, the surrounding air entrainment is enhanced, and spray front end widen. With the increase of mixing ratio, spray penetration increases first, then decreases. The spray cone angle increases after adding n-butanol, and decreases with the increase of mixing ratio. The results show that adding n-butanol can be used as one of the methods to improve biodiesel spray characteristics.

scholarly journals Spray Analysis and Combustion Assessment of Diesel-LPG Fuel Blends in Compression Ignition Engine

Fuels ◽  
2020 ◽  
Vol 2 (1) ◽  
pp. 1-15
Author(s):  
Massimo Cardone ◽  
Renato Marialto ◽  
Roberto Ianniello ◽  
Maurizio Lazzaro ◽  
Gabriele Di Blasio
Keyword(s):  
High Speed ◽  
Internal Combustion Engines ◽  
High Pressures ◽  
Cone Angle ◽  
Cetane Number ◽  
Engine Performance ◽  
Exhaust Emissions ◽  
Compression Ignition Engine ◽  
Spray Cone Angle ◽  
Spray Cone

A major challenge for internal combustion engines (ICEs), and diesel engines, in particular, is the reduction of exhaust emissions, essentially nitrogen oxides (NOx) and particulate matter (PM). In this regard, the potential of LPG-diesel blends was evaluated in this work. The LPG and diesel blends were externally prepared by exploiting their perfect miscibility at high pressures. Two diesel-LPG mixtures with 20% and 35% by mass LPG concentrations were tested. In terms of spatial and temporal evolution, the spray characterization was performed for the two blends and pure diesel fuel through high-speed imaging technique. The combustion behavior, engine performance and exhaust emissions of LPG-diesel blends were evaluated through a test campaign carried out on a single-cylinder diesel engine. Diesel/LPG sprays penetrate less than pure diesel. This behavior results from a lower momentum, surface tension and viscosity, of the blend jets in comparison to diesel which guarantee greater atomization. The addition of LPG to diesel tends to proportionally increase the spray cone angle, due to the stronger turbulent flow interaction caused by, the lower density and low flash-boiling point. Because of improved atomization and mixing during the injection phase, the blends have shown great potential in reducing PM emissions, without affecting engine performance (CO2 emissions). The addition of LPG resulted in a significant smoke reduction (about 95%) with similar NOx emissions and acceptable THC and CO emissions. Furthermore, the low cetane number (CN) and high low-heating value (LHV) ensuring leaner air-fuel mixture, and improvements in terms of efficiency, particularly for a blend with a higher concentration of LPG.

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.

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