Effect of Nanoparticles on the Fuel Properties and Spray Performance of Aviation Turbine Fuel

2016 ◽  
Vol 139 (3) ◽  
Author(s):  
Kumaran Kannaiyan ◽  
Kanjirakat Anoop ◽  
Reza Sadr
Keyword(s):  
Surface Tension ◽  
Physical Properties ◽  
Droplet Diameter ◽  
Cone Angle ◽  
Aviation Fuel ◽  
Alumina Nanoparticles ◽  
Spray Cone Angle ◽  
Spray Cone ◽  
Breakup Length ◽  
Sheet Breakup

The influence of nanoparticles' dispersion on the physical properties of aviation fuel and its spray performance has been investigated in this work. To this end, the conventional Jet A-1 aviation fuel and its mixtures with alumina nanoparticles (nanofuel) at different weight concentrations are investigated. The key fuel physical properties such as density, viscosity, and surface tension that are of importance to the fuel atomization process are measured for the base fuel and nanofuels. The macroscopic spray features like spray cone angle and sheet breakup length are determined using the shadowgraph technique. The microscopic spray characteristics such as droplet diameter, droplet velocity, and their distributions are also measured by employing phase Doppler anemometry (PDA) technique. The spray performance is measured at two nozzle injection pressures of 0.3 and 0.9 MPa. The results show that with the increase in nanoparticle concentrations in the base fuel, the fuel viscosity and density increase, whereas the surface tension decreases. On the spray performance, the liquid sheet breakup length decreases with increasing nanoparticle concentrations. Furthermore, the mean droplet diameters of nanofuel are found to be lower than those of the base fuel.

scholarly journals Experimental Study of Spray Characteristics of Kerosene-Ethanol Blends from a Pressure-Swirl Nozzle

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Tao Zhang ◽  
Bo Dong ◽  
Xun Zhou ◽  
Linan Guan ◽  
Weizhong Li ◽  
...  
Keyword(s):  
Discharge Coefficient ◽  
Cone Angle ◽  
Injection Pressure ◽  
Spray Characteristics ◽  
Spray Cone Angle ◽  
Spray Cone ◽  
Breakup Length ◽  
Ethanol Blends ◽  
Pressure Swirl ◽  
Spray Velocity

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.

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.

scholarly journals CFD simulations of the diesel jet primary atomization from a multihole injector

2017 ◽  
Author(s):  
Charalambos Chasos
Keyword(s):  
High Pressure ◽  
Nozzle Exit ◽  
Cone Angle ◽  
Injection Pressure ◽  
Liquid Jet ◽  
Spray Cone Angle ◽  
Two Phase ◽  
Spray Cone ◽  
Breakup Length ◽  
Jet Breakup

High pressure multi-hole diesel injectors are currently used in direct-injection common-rail diesel engines for the improvement of fuel injection and air/fuel mixing, and the overall engine performance. The resulting spray injection characteristics are dictated by the injector geometry and the injection conditions, as well as the ambient conditions into which the liquid is injected. The main objective of the present study was to design a high pressure multi-hole diesel injector and model the two-phase flow using the volume of fluid (VOF) method, in order to predict the initial liquid jet characteristics for various injection conditions. A computer aided design (CAD) software was employed for the design of the three-dimensional geometry of the assembly of the injector and the constant volume chamber into which the liquid jet emerges. A typical six-hole diesel injector geometry was modelled and the holes were symmetrically located around the periphery of the injector tip. The injector nozzle diameter and length were 0.2 mm and 1 mm, respectively, resulting in a ratio of nozzle orifice length over nozzle diameter L/D = 5. The commercial computational fluid dynamics (CFD) code STAR-CD was used for the generation of the computational mesh and for transient simulations with an Eulerian approach incorporating the VOF model for the two-phase flow and the Rayleigh model for the cavitation phenomenon. Three test cases for increasing injection pressure of diesel injection from the high pressure multi-hole diesel injector into high pressure and high temperature chamber conditions were investigated. From the injector simulations of the test cases, the nozzle exit velocity components were determined, along with the emerging liquid jet breakup length at the nozzle exit. Furthermore, the spray angle was estimated by the average radial displacement of the liquid jet and air mixture at the vicinity of the nozzle exit. The breakup length of the liquid jet and the spray cone angle which were determined from the simulations, were compared with the breakup length and cone angle estimated by empirical equations. From the simulations, it was found that cavitation takes place at the nozzle inlet for all the cases, and affects the fuel and air interaction at the upper area of the spray jet. Furthermore, the spray jet breakup length increases with elapsed time, and when the injection pressure increases both the breakup length and the spray cone angle increase.DOI: http://dx.doi.org/10.4995/ILASS2017.2017.5040

Spray Characteristics of Swirl Effervescent Injector in Rocket Application: A Review

2012 ◽  
Vol 225 ◽  
pp. 423-428
Author(s):  
Zulkifli Abdul Ghaffar ◽  
Ahmad Hussein Abdul Hamid ◽  
Mohd Syazwan Firdaus Mat Rashid
Keyword(s):  
Combustion Chamber ◽  
Rocket Engine ◽  
Cone Angle ◽  
Operating Conditions ◽  
Spray Characteristics ◽  
Spray Cone Angle ◽  
Spray Cone ◽  
Breakup Length ◽  
Mixing Chamber ◽  
Discharge Orifice

Injector is one of the vital devices in liquid rocket engine (LRE) as small changes in its configurations and design can result in significantly different LRE performance. Characteristics of spray such as spray cone angle, breakup length and Sauter mean diameter (SMD) are examples of crucial parameters that play the important role in the performance of liquid propellant rocket engine. Wider spray cone angle is beneficial for widespread of fuel in the combustion chamber for fast quiet ignition and a shorter breakup length provides shorter combustion chamber to be utilized and small SMD will result in fast and clean combustion. There are several mechanisms of liquid atomization such as swirling, e.g. jet swirl atomization or introducing bubbles into the liquid and effervescent atomization. Introducing a swirl component in the flow can enhance the propellant atomization and mixing whereas introducing bubbling gas directly into the liquid stream inside the injector leads to finer sprays even at lower injection pressures. This paper reviews the influence of both operating conditions and injector internal geometries towards the spray characteristics of swirl effervescent injectors. Operating conditions reviewed are injection pressure and gas-to-liquid ratio (GLR), while the injector internal geometries reviewed are limited to swirler geometry, mixing chamber diameter (dc), mixing chamber length (lc), aeration hole diameter (da), discharge orifice diameter (do) and discharge orifice length (lo).

Characteristics of Hollow Cone Swirl Spray at Various Nozzle Orifice Diameters

2012 ◽  
Vol 58 (2) ◽  
Author(s):  
A. Hussein ◽  
M. Hafiz ◽  
H. Rashid ◽  
A. Halim ◽  
W. Wisnoe ◽  
...  
Keyword(s):  
Discharge Coefficient ◽  
Cone Angle ◽  
Injection Pressure ◽  
Orifice Diameter ◽  
Hollow Cone ◽  
Spray Characteristics ◽  
Spray Cone Angle ◽  
Spray Cone ◽  
Nozzle Orifice ◽  
Breakup Length

An experimental work to investigate the swirl spray characteristics that emanates from hollow–cone and solid–cone spray simplex atomizers is presented. Main objective of the research is to investigate the spray characteristics, i.e. spray breakup length, discharge coefficient and spray cone angle at different nozzle orifice diameter and injection pressure. Discharge coefficient is almost uninfluenced by the operating Reynolds number. This test also reveals that both breakup length and spray cone angle increases as orifice diameter is increased. Higher injection pressure leads to shorter breakup length and wider spray cone angle.

scholarly journals Experimental Characterization of Two-Phase Aerated Liquid Ethanol and Jet A Spray Flames

2020 ◽  
Vol 10 (19) ◽  
pp. 6950
Author(s):  
Cary Smith ◽  
Mark Gragston ◽  
Yue Wu ◽  
Zhili Zhang
Keyword(s):  
Cone Angle ◽  
Mie Scattering ◽  
Aviation Fuel ◽  
Flame Height ◽  
Size Spectrum ◽  
Spray Cone Angle ◽  
Two Phase ◽  
Spray Cone ◽  
Spray Flames ◽  
Fuel Jet

This work provides an analysis of an air-assisted atomizing nebulizer’s spray characteristics and combustion behaviors via application of various diagnostics. Two-phase far-field flows and flames of liquid ethanol and practical aviation fuel Jet A were characterized for the droplet distributions, fuel concentrations, and flame dynamics by shadowgraph, Mie scattering, and chemiluminescence imaging of CH*, C2*, and CO2*. Both instantaneous and time-averaged measurements of the two-phase flow and flame characteristics were obtained. Shadowgraphs were used to measure the probability distribution of the droplet diameters. Mie scattering was used to map fuel concentration and obtain the liquid spray cone angles. Estimates of the lifted flame height were obtained by both shadowgraph and Mie scattering, which were verified by the chemiluminescence images. The effect of flow rates on parameters such as flow characteristic, spray cone angle, and drop size spectrum were quantitatively characterized for both ethanol and practical aviation fuel Jet A.

Effect of geometric and operating parameters on the spray characteristics of an open-end swirl injector

2019 ◽  
Vol 233 (12) ◽  
pp. 4457-4467 ◽  
Author(s):  
Chen Chen ◽  
Yang Yang ◽  
Xiaorong Wang ◽  
Wenxian Tang
Keyword(s):  
Pressure Drop ◽  
Discharge Coefficient ◽  
Cone Angle ◽  
Injection Pressure ◽  
Operating Parameters ◽  
Spray Cone Angle ◽  
Spray Cone ◽  
Breakup Length ◽  
Swirl Chamber ◽  
Swirl Injector

To study the influence of geometric and operating parameters on the spray characteristics of an open-end swirl injector, seven injectors with different tangential inlet diameters ( D p) and injector length to injector orifice diameter ( L/D) ratios were tested and simulated. Using high-speed backlight, the evolution laws of liquid film thickness, discharge coefficient, spray cone angle, breakup length, and velocity distribution in the swirl chamber under different geometric and operating parameters were captured after unified image processing. Low-injection pressure drop is directly proportional to the discharge coefficient and the spray cone angle. When the injection pressure drop approaches or reaches a critical value of 0.4 MPa, the discharge coefficient and spray cone angle remain nearly constant with maximum fluctuations of 1% and 5%, respectively. With an increase in the geometric characteristic constant A, the liquid film thickness, discharge coefficient, breakup length, and velocity in the swirl chamber decrease, whereas the spray cone angle increases. As the viscous effect increases for increasing L/D, the discharge coefficient and breakup length increase, whereas the spray cone angle decreases. Based on experiment results, empirical formulas for the discharge coefficient, spray angle, and breakup length were put forward as reference for engineering applications, including the effect of the geometric and operating parameters.

Study of Two Miniature Air-Assist Atomizers With Radial and Axial Air Swirlers

2006 ◽  
Author(s):  
Y. Levy ◽  
V. Sherbaum ◽  
V. Ovcharenko ◽  
V. Nadvani
Keyword(s):  
Droplet Size ◽  
Droplet Diameter ◽  
Cone Angle ◽  
Droplet Size Distribution ◽  
Spray Angle ◽  
Air Velocity ◽  
Liquid Pressure ◽  
Spray Cone Angle ◽  
Spray Cone ◽  
Air Channels

The performances of two types of miniature air-assist atomizers were investigated; one with air being directed to the liquid spray through radial-tangential air channels and the other with air supplied through a small axial swirler. The study has shown that droplet size is reduced significantly when the air velocity increases up to about 50 m/s. However, further increase in air velocity has only a weak effect on the droplet size. In the absence of air supply, elevating the liquid pressure causes a reduction in the droplet diameter. The maximum values of the droplet mass flux shifts to the spray periphery with increasing of air velocity. In the air-assist operational regime, the liquid pressure has a slight effect on SMD however; the spray cone angle is increased significantly and can achieve values of up to 120 degrees for low liquid pressure drop. The larger spray angle at comparable droplet size distribution makes the atomizers with the radial air swirlers more favorable for small jet engines.

Method of Identifying Injector Coking From the Spray Field of Mechanical and CRDi Injectors Using Intensity of Scattered Light

2017 ◽  
Vol 140 (2) ◽  
Author(s):  
Ronith Stanly ◽  
Gopakumar Parameswaran ◽  
Bibin Sagaram
Keyword(s):  
Scattered Light ◽  
Near Field ◽  
Cone Angle ◽  
Angle Measurement ◽  
Field Region ◽  
Fuel System ◽  
Spray Cone Angle ◽  
Spray Cone ◽  
Cleaning Procedure ◽  
Spray Field

The influence of injector coking deposits on the spray field of single-hole mechanical port fuel injectors and multihole common rail direct injection (CRDi) injectors was studied using light scattering technique coupled with image processing and analysis. Instead of employing the traditional accelerated coking process to study injector spray field deterioration, in-service injectors were selected and cleaned using a commercial fuel system cleaning procedure. Variation in atomization characteristics of coked and cleaned injectors were observed based on the spatial distribution of fine, medium, and coarse droplets in the near-field region of the injector spray zone and analyzed as a function of the intensity of scattered light. The improvement in the atomization perceived by this method was compared with traditional techniques like spray cone angle measurement, speed characterization of spray jets, and weight reduction of injector nozzles and needles. It was observed that after the fuel system cleaning procedure, a reduction in the number of coarse droplets in the near-field region and an increase in the number of medium and finely sized droplets was observed, suggesting better atomization of fuel in the near field spray zone.

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