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

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.

2020 ◽  
Vol 40 (04) ◽  
Author(s):  
VO TAN CHAU

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.


Author(s):  
Bong Woo Ryu ◽  
Seung Hwan Bang ◽  
Hyun Kyu Suh ◽  
Chang Sik Lee

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.


Author(s):  
Fengyu Li ◽  
Bolun Yi ◽  
Lanbo Song ◽  
Wei Fu ◽  
Tao Liu ◽  
...  

In this research, three basic macroscopic spray characteristics (spray tip penetration, spray cone angle, and spray area) of long-chain alcohol-biodiesel blends were studied to investigate the differences of macroscopic spray characteristics of long-chain alcohol-biodiesel blends with different mixing ratios and to further investigate the effects of blending long-chain alcohols into biodiesel on the spray characteristics. Two kinds of long-chain alcohols, n-butanol, and n-pentanol, were selected to study effects of difference kinds of long-chain alcohols on macroscopic spray characteristics of long-chain alcohol-biodiesel blends. Results show that with the increase of proportion of n-butanol or n-pentanol in blends, spray tip penetration decreased while spray cone angle and spray area increased; in terms of the effects brought by different long-chain alcohols, n-pentanol-biodiesel blends showed slightly longer spray tip penetration, smaller spray cone angle and smaller spray area compared to n-butanol-biodiesel blends in the same mixing ratios, and the difference trends between those two kinds blends could easily be opposite due to the very similar properties of n-butanol and n-pentanol. Furthermore, a modified spray tip penetration model was proposed based on previous model and showed good agreement with experimental results.


Author(s):  
Shenghao Yu ◽  
Bifeng Yin ◽  
Shuai Wen ◽  
Xifeng Li ◽  
Hekun Jia ◽  
...  

The early stage spray characteristics have a great impact on the secondary atomization progress, and thus affectthe engine combustion and emission performances. The experimental investigation of the early stage spray behaviors with biodiesel and diesel was carried out by employing a laser-based Mie-scattering method. The results show that the spray tip penetration for biodiesel is higher than that for diesel at the early stage spray under the same injection pressure. Moreover, the early stage spray tip penetration can be longer under high injection pressures for two fuels. Besides, the early stage spray cone angle for biodiesel is narrower than that for diesel, and the spray cone angle is especially higher than biodiesel by 25.8% after start of injection time of 0.01ms. Furthermore, under the same injection condition, the difference of early stage spray area between diesel and biodiesel is not obvious, while the spray volume for biodiesel is larger than that for diesel, and also the sprayvolume can be enlarged by increasing injection pressure for both fuels.DOI: http://dx.doi.org/10.4995/ILASS2017.2017.4651


Author(s):  
Bolun Yi ◽  
Wei Fu ◽  
Lanbo Song ◽  
Fengyu Li ◽  
Tao Liu ◽  
...  

The aim of this study was to investigate the spray characteristics of biodiesel and n-butanol/biodiesel blended fuel. The spray tip penetration and the spray cone angle were tested and analyzed. A constant volume chamber and high-speed camera were used to observe the spray evolution and a common-rail system was employed to change the injection pressure. The results show that the spray tip penetration and the spray cone angle of biodiesel are larger than those of blended fuel in most cases. n-Butanol additive changes the relationship between angle and density ratio to a certain degree. The experimental trend lines support the penetration model proposed by Hiroyasu and Arai in terms of similar proportional relation on time after start of injection, and the empirical equations provide reasonable agreement with the experimental data of the spray tip penetration.


2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Tao Zhang ◽  
Bo Dong ◽  
Xun Zhou ◽  
Linan Guan ◽  
Weizhong Li ◽  
...  

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.


2020 ◽  
pp. 146808742091471
Author(s):  
Feng Li ◽  
Chia-fon Lee ◽  
Ziman Wang ◽  
Yiqiang Pei ◽  
Guoxiang Lu

Ducted fuel injection spray is a new technology for reducing soot formation in heavy-duty diesel engines. In this work, the ducted fuel injection spray characteristics with different duct inner diameters and different standoff distances were investigated and compared with free spray. Duct inner diameter ranged from 1.5 to 4 mm, and standoff distance varied between 0.9 and 4.9 mm. Mie-scattering optical technique was used to characterize spray characteristics under various injection pressures in a constant-volume spray chamber. Ambient gas pressure of up to 6 MPa when spraying. The results showed that ducted fuel injection spray with smaller duct has better spray diffusion compared to those of ducted fuel injection sprays with larger ducts and free spray from the perspectives of spray tip penetration, spray cone angle and spray area. Increasing standoff distance could increase spray velocity. Ducted fuel injection spray with smaller duct formed a mushroom-shaped head and large-scale vortex flow close to the duct outlet. All the advantages of ducted fuel injection spray with smaller duct are interpreted as evidence of improving fuel–gas mixing quality significantly.


Author(s):  
Jaclyn E. Johnson ◽  
Jeffrey D. Naber ◽  
Seong-Young Lee

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.


2014 ◽  
Vol 984-985 ◽  
pp. 932-937 ◽  
Author(s):  
Palani Raghu ◽  
M. Senthamil Selvan ◽  
K. Pitchandi ◽  
N. Nallusamy

— 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.


Author(s):  
Wei Fu ◽  
Lanbo Song ◽  
Tao Liu ◽  
Qizhao Lin

The objective of this paper is to investigate the spray macroscopic characteristics of biodiesel, diethyl carbonate (DEC)-biodiesel blends and diesel fuel based on a common-rail injection system. The spray tip penetration, spray cone angle and the spray projected area were measured through a high-speed photography method. The experimental results reveal that injection pressure and ambient pressure have significant effects on the spray characteristics. Higher injection pressure makes the spray tip penetration increase, while higher back pressure inside the chamber leads to the enlargement of the spray cone angle. The addition of DEC causes the blends fuels to have a shorter penetration and larger spray projected area, which reveals the potential capacity to improve the atomization process compared with biodiesel. The estimation of spray droplet size indicates that DEC30 generates a smaller Sauter mean diameter (SMD) because of its lower surface tension and viscosity. Model predictions were illustrated and compared with current work.


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