Droplet deformation and breakup in shear flow of air

Xu, Zhikun; Wang, Tianyou; Che, Zhizhao

doi:10.1063/5.0006236

Cited by 44 publications

(9 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

Section: Resultsmentioning

confidence: 99%

“…To extend our results, the flow properties of the system are analyzed with two essential control parameters, i . e ., the Weber number ( We ) and the Ohnesorge number ( Oh ), commonly used in microfluidic , and droplet formation . The Weber number, We = ρ o v 2 d D /γ, represents the ratio of the disrupting inertial force to the restorative surface tension force, where ρ o and v are the density and the relative velocity of the ambient fluid (decane oil) and d D and γ are the diameter and the interfacial tension of the droplet, respectively.…”

Section: Results and Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Armored Droplets as Soft Nanocarriers for Encapsulation and Release under Flow Conditions

Sicard

Toro-Mendoza

2021

ACS Nano

View full text Add to dashboard Cite

Technical challenges in precision medicine and environmental remediation create an increasing demand for smart materials that can select and deliver a probe load to targets with high precision. In this context, soft nanomaterials have attracted considerable attention due to their ability to simultaneously adapt their morphology and functionality to complex ambients. Two major challenges are to precisely control this adaptability under dynamic conditions and provide predesigned functionalities that can be manipulated by external stimuli. Here, we report on the computational design of a distinctive class of soft nanocarriers, built from armored nanodroplets, able to selectively encapsulate or release a probe load under specific flow conditions. First, we describe in detail the mechanisms at play in the formation of pocket-like structures in armored nanodroplets and their stability under external flow. Then we use that knowledge to test the capacity of these pockets to yield flow-assisted encapsulation or expulsion of a probe load. Finally, the rheological properties of these nanocarriers are put into perspective with those of delivery systems employed in pharmaceutical and cosmetic technology.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Results and Discussionmentioning

confidence: 99%

Armored Droplets as Soft Nanocarriers for Encapsulation and Release under Flow Conditions

Sicard

Toro-Mendoza

2021

ACS Nano

View full text Add to dashboard Cite

show abstract

“…Thereafter, on injection into the cross-flow, the liquid fuel further disintegrates into smaller droplets mainly due to aerodynamic shear causing secondary atomization. 50 Figure 15 depicts the comparative spray structure of Jet A-1 liquid and gel fuel injected transversely into the cross-flowing airstream environment using an IIAB atomizer. Both an aerodynamic force as well as the design of the atomizer influences the break-up mechanism of both fuels.…”

Section: Flow Physics Of Jet A-1 Liquid and Gel Fuel Break-up In Low-...mentioning

confidence: 99%

Effect of atomizer and cross-flows on liquid and gelled Jet A-1 fuel injection

Pandian,

Das

2023

International Journal of Engine Research

View full text Add to dashboard Cite

The current study aims to experimentally investigate the effect of atomizer and cross-flow velocities on liquid and gelled Jet A-1 fuels. For gelled Jet A-1, Jet A-1 liquid, Thixatrol® ST and rectified xylene are the base fuel, gellant and solvent, respectively. Gelled Jet A-1 is prepared by adding 85% by weight of base fuel along with 7.5% by weight of gellant and solvent, each at optimum processing conditions. Atomization using a simple-plain-orifice atomizer is investigated to understand its effect on Jet A-1 gel fuel break-up without air cross-flow. Based on the investigation from qualitative flow visualization and quantitative analysis of Jet A-1 gel fuel break-up, a modified simple-plain-orifice atomizer called an internally impinging air-blast atomizer is made. Primary atomization using this new atomizer is studied to understand the break-up of liquid and gelled Jet A-1 gel fuels without any air cross-flow. Secondary atomization of liquid and gel fuel is investigated by transversely injecting fuel into different low-speed subsonic air cross-flow environments. Laser sheet Imaging (LSI) technique is used to capture spray images of both fuels. Break-up mechanisms of both liquid and gel fuels were observed, and the results were compared. Information on the cross-flow air mass flow rate effect on the liquid and gel spray is extracted by developing an algorithm in MATLAB using an image processing tool. Relative droplet size distribution of liquid and gel spray revealed their dependence on cross-flow air mass flow rate. Total droplet count of both liquid and gel fuel decreases significantly as the cross-flow Reynolds’ number increases. At higher cross-flow Reynolds’ number, gel droplets in the flow are observed to be more as compared to liquid fuel.

show abstract

“…Droplets are generated when surface fluid is detached and fragmented in the strong airflows of sneezing, coughing, and speech (25,26). Fragmentation continues in the shear field of the violently expelled air (37,65), prolonged by the viscoelasticity of the mucus polymers (66). In turbulent airflows, collisions between droplets can lead to either fragmentation or coalescence.…”

Section: Coalescence and Fragmentation Of Dropletsmentioning

confidence: 99%

Aerosol Transmission of SARS-CoV-2: Physical Principles and Implications

Jarvis

2020

Front. Public Health

131

116

View full text Add to dashboard Cite

Evidence has emerged that SARS-CoV-2, the coronavirus that causes COVID-19, can be transmitted airborne in aerosol particles as well as in larger droplets or by surface deposits. This minireview outlines the underlying aerosol science, making links to aerosol research in other disciplines. SARS-CoV-2 is emitted in aerosol form during normal breathing by both asymptomatic and symptomatic people, remaining viable with a half-life of up to about an hour during which air movement can carry it considerable distances, although it simultaneously disperses. The proportion of the droplet size distribution within the aerosol range depends on the sites of origin within the respiratory tract and on whether the distribution is presented on a number or volume basis. Evaporation and fragmentation reduce the size of the droplets, whereas coalescence increases the mean droplet size. Aerosol particles containing SARS-CoV-2 can also coalesce with pollution particulates, and infection rates correlate with pollution. The operation of ventilation systems in public buildings and transportation can create infection hazards via aerosols, but provides opportunities for reducing the risk of transmission in ways as simple as switching from recirculated to outside air. There are also opportunities to inactivate SARS-CoV-2 in aerosol form with sunlight or UV lamps. The efficiency of masks for blocking aerosol transmission depends strongly on how well they fit. Research areas that urgently need further experimentation include the basis for variation in droplet size distribution and viral load, including droplets emitted by “superspreader” individuals; the evolution of droplet sizes after emission, their interaction with pollutant aerosols and their dispersal by turbulence, which gives a different basis for social distancing.

show abstract

Droplet deformation and breakup in shear flow of air

Cited by 44 publications

References 47 publications

Armored Droplets as Soft Nanocarriers for Encapsulation and Release under Flow Conditions

Armored Droplets as Soft Nanocarriers for Encapsulation and Release under Flow Conditions

Effect of atomizer and cross-flows on liquid and gelled Jet A-1 fuel injection

Aerosol Transmission of SARS-CoV-2: Physical Principles and Implications

Contact Info

Product

Resources

About