Effect of Various Injection Pressures on Spray Characteristics of Karanja Oil Methyl Ester (KOME) and Diesel in a DI Diesel Engine

2015 ◽  
Vol 787 ◽  
pp. 815-819
Author(s):  
Vaibhav Prakash ◽  
B. Praveen Ramanujam ◽  
C. Sanjeev Nivedan ◽  
N. Nallusamy ◽  
P. Raghu

The performance and emissions from diesel engines are greatly influenced by the degree of atomization of the fuel spray. The characteristics of the spray affect the physics of formation of the air-fuel mixture. They depend on density and viscosity of fuel, injection pressure, pressure and temperature of fuel. The spray structure is primarily dependent on the fuel injection pressure. This study involves the carrying out of experimental investigations on biodiesel and diesel fuel sprays in a DI diesel engine for different injection pressures. The spray cone angle and spray tip penetration length are studied experimentally. Using spray visualization system and image processing techniques, the experimental data is obtained. The fuels used are Karanja oil methyl ester (KOME) and diesel. The experimental results show that, as the injection pressure increases, the spray cone angle decreases for KOME and similar trends are observed with diesel. In addition, spray penetration length increases with increase in injection pressure and the value of the same was slightly higher for KOME than that of diesel. The results also reveal similarities in spray characteristics of both the test fuels.

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0255874
Author(s):  
Hua Xia

The internal flow and macroscopic spray behaviors of a fuel injection process were studied with schlieren spray techniques and simulations. The injection pressures(Pin)and ambient pressures(Pout)were applied in a wide range. The results showed that increasing the Pin is likely to decrease the flow performance of the nozzle. Furthermore, increasing the Pin can increase the spray tip penetration. However, the effect of Pin on the spray cone angle was not evident. The spray cone angle at an injection pressure of 160MPa was 21.7% greater than at a pressure of 100MPa during the initial spraying stage. Additionally, the discharge coefficient increased under high Pout, and the decrease in Pout can promote the formation of cavitation. Finally, increasing the Pout can decrease the penetration, while the spray angle becomes wider, especially at the initial spray stage, and high Pout will enhance the interaction of the spray and the air, which can enhance the spray quality.


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):  
Kemar C. James ◽  
Jin Wang ◽  
Zackery B. Morris ◽  
Michael C. Maynard ◽  
Brian T. Fisher

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.


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.


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.


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