scholarly journals Penetration and secondary atomization of droplets impacted on wet facemasks

2021 ◽  
Vol 6 (11) ◽  
Author(s):  
Sombuddha Bagchi ◽  
Saptarshi Basu ◽  
Swetaprovo Chaudhuri ◽  
Abhishek Saha
Keyword(s):  
Secondary Atomization

Experimental characterization of secondary atomization at high Ohnesorge numbers

2021 ◽  
Vol 138 ◽  
pp. 103591
Author(s):  
Vishnu Radhakrishna ◽  
Weixiao Shang ◽  
Longchao Yao ◽  
Jun Chen ◽  
Paul E. Sojka
Keyword(s):  
Experimental Characterization ◽  
Secondary Atomization

scholarly journals Secondary atomization behavior and size distribution of emulsified fuel in spray flow under N2

2015 ◽  
Vol 81 (827) ◽  
pp. 15-00128-15-00128 ◽  
Author(s):  
Yutaka SHOJI ◽  
Hirotatsu WATANABE ◽  
Ken OKAZAKI
Keyword(s):  
Size Distribution ◽  
Secondary Atomization ◽  
Emulsified Fuel

Fuel Efficiency – Challenges and Innovations in Emulsified Fuel Technology

2015 ◽  
Author(s):  
Jerry Ng ◽  
Kaisa Honkanen
Keyword(s):  
Diesel Engines ◽  
Fuel Injection ◽  
Fuel Efficiency ◽  
Combustion Efficiency ◽  
Secondary Atomization ◽  
Emulsified Fuel ◽  
Main Challenge ◽  
Marine Diesel ◽  
Initial Fuel ◽  
Fuel Technology

Emulsified fuel technology has been developed since the early 1980’s to the improve combustion efficiency of marine diesel engines by creating a secondary atomization effect after the initial fuel injection. The main challenge is to measure the improved sfoc of ships accurately and reliably. This paper presents a proposed method to measure the sfoc accurately and reliably to the order of 1%. Electronic governor also poses new challenge to measuring the sfoc of ships burning emulsified fuel. Meanwhile, fuel types supplied to ship owners are of increased varying properties although still complying to ISO8217 standard. This paper describes the innovations in emulsified fuel technology that were developed to meet these challenges.

Shock waves in sprays: numerical study of secondary atomization and experimental comparison

Shock Waves ◽  
2015 ◽  
Vol 26 (4) ◽  
pp. 403-415 ◽  
Author(s):  
A. Chauvin ◽  
E. Daniel ◽  
A. Chinnayya ◽  
J. Massoni ◽  
G. Jourdan
Keyword(s):  
Shock Waves ◽  
Numerical Study ◽  
Experimental Comparison ◽  
Secondary Atomization

scholarly journals Investigation of Puffing and Micro-Explosion of Water-in-Diesel Emulsion Spray Using Shadow Imaging

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2281 ◽  
Author(s):  
Mhadi A. Ismael ◽  
Morgan Heikal ◽  
A. A. Aziz ◽  
Cyril Crua ◽  
Mohmmed El-Adawy ◽  
...  
Keyword(s):  
Droplet Size ◽  
High Speed ◽  
Elevated Temperatures ◽  
Injection Pressure ◽  
Image Processing Algorithm ◽  
Long Distance ◽  
Secondary Atomization ◽  
High Injection ◽  
Digital Microscope ◽  
Injection Pressures

Water-in-diesel emulsions potentially favor the occurrence of micro-explosions when exposed to elevated temperatures, thereby improving the mixing of fuels with the ambient gas. The distributions and sizes of both spray and dispersed water droplets have a significant effect on puffing and micro-explosion behavior. Although the injection pressure is likely to alter the properties of emulsions, this effect on the spray flow puffing and micro-explosion has not been reported. To investigate this, we injected a fuel spray using a microsyringe needle into a high-temperature environment to investigate the droplets’ behavior. Injection pressures were varied at 10% v/v water content, the samples were imaged using a digital microscope, and the dispersed droplet size distributions were extracted using a purpose-built image processing algorithm. A high-speed camera coupled with a long-distance microscope objective was then used to capture the emulsion spray droplets. Our measurements indicated that the secondary atomization was significantly affected by the injection pressure which reduced the dispersed droplet size and hence caused a delay in puffing. At high injection pressure (500, 1000, and 1500 bar), the water was evaporated during the spray and although there was not enough droplet residence time, puffing and micro-explosion were clearly observed. This study suggests that high injection pressures have a detrimental effect on the secondary atomization of water-in-diesel emulsions.

Transition Weber number between surfactant-laden drop bag breakup and shear breakup of secondary atomization

Fuel ◽  
2018 ◽  
Vol 221 ◽  
pp. 138-143 ◽  
Author(s):  
Hui Zhao ◽  
Zhao-Wei Wu ◽  
Wei-Feng Li ◽  
Jian-Liang Xu ◽  
Hai-Feng Liu
Keyword(s):  
Weber Number ◽  
Secondary Atomization

Influence of density ratio on the secondary atomization of liquid droplets under highly unstable conditions

Fuel ◽  
2016 ◽  
Vol 174 ◽  
pp. 25-35 ◽  
Author(s):  
Wei Yang ◽  
Ming Jia ◽  
Kai Sun ◽  
Tianyou Wang
Keyword(s):  
Density Ratio ◽  
Liquid Droplets ◽  
Secondary Atomization

Impingement of an unsteady two-phase jet on unheated and heated flat plates

1993 ◽  
Vol 252 ◽  
pp. 499-523 ◽  
Author(s):  
İ. Bedii Özdemir ◽  
J. H. Whitelaw
Keyword(s):  
Wall Temperature ◽  
High Speed ◽  
Continuous Phase ◽  
Size Class ◽  
Wall Jet ◽  
Flat Plates ◽  
Two Phase ◽  
Secondary Atomization ◽  
Wall Jet Flow ◽  
The Impact

This paper is concerned with an experimental investigation of the oblique impingement of an unsteady, axisymmetric two-phase jet on heated surfaces. Size and velocity were measured simultaneously with a phase-Doppler velocimeter, and the spatial distributions over the wall jet were found to be correlated with the interfacial activities as inferred from vertical velocity measurements in the vicinity of the wall. These results are discussed together with size measurements by a laser-diffraction technique to quantify the effect of the approach conditions of the inflowing jet droplet field and wall temperature in relation to mechanisms of secondary atomization.Two mechanisms of secondary atomization were identified; the first did not involve direct wall contact and was due to the strain acting on the droplets by the continuous phase within the impingement region and was enhanced by thermal effects from the wall to cause breakup. The approaching velocity of the inflowing droplets to the plate was important to this process so that higher velocities increased the rate of strain within the impingement region and, consequently, the wall temperature promoting the secondary atomization shifted towards lower values. The second mechanism required direct wall contact and involved atomization of the film deposited on the wall by the impingement of the inflowing two-phase jet. With the penetration of high-speed inflowing droplets into the film, liquid mass was raised into the two-phase medium due to splashes from the film so that a new size class with larger droplets was generated. The resulting large droplets tended to stay close to the wall within the impingement region with small vertical velocitiesIn between the injections, the suspended droplet field above the film oscillated normal to the plate as a cloud so that the impact of large droplets on the film resulted in coalescence with the film and the ejection of smaller numbers of small droplets. The unsteady wall jet flow, caused by the arrival of the spray at the plate, swept the vertically oscillating droplet cloud radially outwards so that the resulting radial transport caused the dynamics of the unsteady film to be correlated with the size characteristics of the unsteady wall jet. Based on this phenomenological description, a radial droplet transport equation is derived.The correlation suggests that the secondary atomization with direct wall contact is the dominant process for the generation of a new size class within the wall flow and initiates the mutual interaction between the unsteady film and wall jet droplet field.

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