The influence of Saffman lift force on nanoparticle concentration distribution near a wall

In magnetic nanoparticle hyperthermia for cancer treatment, controlling nanoparticle is vital for managing heat deposition and temperature elevations in clinical applications. In this study, we first perform a numerical simulation of magnetic nanofluid transport in agarose gel during an injection process and explore the relationship between the spreading shapes of the nanofluid in gel and injection parameters. We also simulate the nanoparticle concentration distribution in tissues after being injected into the extracellular space under various injection parameters. The model consists of two components. One is a particle trajectory tracking model (PTTM) which can predict the deposition rate of nanoparticle on the porous matrix in a single pore structure by using a Lagrangian Brownian Dynamics simulation method. The other one is a macroscale transport model of nanofluid in saturated porous structures. This study provides advanced understanding of nanofluid transport behavior in a porous structure. Our results show that the gap formed surrounding the needle may cause a back flow and can significantly affect the shape of nanofluid spreading. For small-sized nanoparticle (10nm) with zero surface zeta potential, the filtration effect dominates the particle distribution. The effect of other conditions like nanoparticle size, particle surface coating, and physic-chemical properties of carrier fluid on nanoparticle concentration distribution is under study.

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Lateral particle size segregation in a riser under core annular flow conditions due to the Saffman lift force

Powder Technology ◽

10.1016/j.powtec.2016.05.047 ◽

2016 ◽

Vol 299 ◽

pp. 119-126 ◽

Cited By ~ 2

Author(s):

Ronald W. Breault ◽

Steven L. Rowan ◽

Esmail Monazam ◽

Kyle T. Stewart

Keyword(s):

Particle Size ◽

Lift Force ◽

Annular Flow ◽

Flow Conditions ◽

Size Segregation ◽

Saffman Lift Force

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Predicting the deposition spot radius and the nanoparticle concentration distribution in an electrostatic precipitator

Aerosol Science and Technology ◽

10.1080/02786826.2020.1716939 ◽

2020 ◽

Vol 54 (6) ◽

pp. 718-728 ◽

Cited By ~ 2

Author(s):

Calle Preger ◽

Niels C. Overgaard ◽

Maria E. Messing ◽

Martin H. Magnusson

Keyword(s):

Concentration Distribution ◽

Electrostatic Precipitator ◽

Nanoparticle Concentration ◽

Spot Radius

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Diffusion characteristics of the industrial submicron particle under Brownian motion and turbulent diffusion

Indoor and Built Environment ◽

10.1177/1420326x21991055 ◽

2021 ◽

pp. 1420326X2199105

Author(s):

Chengjun Li ◽

Hanqing Wang ◽

Chuck Wah Yu ◽

Dong Xie

Keyword(s):

Heat Source ◽

Drag Force ◽

Lift Force ◽

Aerosol Particles ◽

Particle Model ◽

Thermal Plume ◽

Submicron Aerosol ◽

Brownian Force ◽

The Impact ◽

Saffman Lift Force

The industrial release of submicron aerosol particles at workplace could cause undue health effect on workers. To effectively capture and remove airborne particles, we need to study the characteristics of various interactive particle motion forces (drag force, Brownian force, Saffman lift force, etc.) and the dispersion of these aerosol particles in indoor air. In this study, the dominant force of submicron particles was determined by calculating the acting forces with different particle sizes. Then, a Discrete Particle Model (DPM) was used to calculate the trajectory of particle movement in turbulent thermal plume flow. Horizontal dispersity ( DH) was defined to evaluate the horizontal diffusion of the particulate matter. The impact of different particle diameters, heat source temperatures and initial relative velocities on DH was investigated. This study showed that the main acting forces for submicron aerosol particles were drag force, Brownian force, Saffman lift force and thermophoresis force. Brownian force cannot be ignored when the particle diameter was below 0.3 µm, which would promote the irregular movement of particles in space and enhance their diffusion ability. The smaller the particle size, the higher the heat source temperature and the lower the particles' initial velocity would lead to the increase of DH.

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Influencing Factors on Submicron Particle Movement Patterns in Supersonic Laminar Boundary Layers

Volume 1D, Symposia: Transport Phenomena in Mixing; Turbulent Flows; Urban Fluid Mechanics; Fluid Dynamic Behavior of Complex Particles; Analysis of Elementary Processes in Dispersed Multiphase Flows; Multiphase Flow With Heat/Mass Transfer in Process Technology; Fluid Mechanics of Aircraft and Rocket Emissions and Their Environmental Impacts; High Performance CFD Computation; Performance of Multiphase Flow Systems; Wind Energy; Uncertainty Quantification in Flow Measurements and Simulations ◽

10.1115/fedsm2014-21166 ◽

2014 ◽

Author(s):

Xing Li ◽

Bofeng Bai

Keyword(s):

Boundary Layer ◽

Mach Number ◽

Boundary Layers ◽

Drag Force ◽

Lift Force ◽

Particle Movement ◽

Submicron Particle ◽

Laminar Boundary Layers ◽

Saffman Lift Force ◽

Supersonic Laminar

The process of submicron particle movement in laminar boundary layers is present in many practical applications such as the particles depositing on the turbine blade and mist droplets depositing on the surface of aircrafts. Although great progress has been made on this issue during the last decades, many underlying mechanisms still remain unclear. Here, we developed a theoretical model to understand how submicron particles will behave when they enter a supersonic laminar boundary layer above an adiabatic plate along with the main stream. In this model, we used the Lagrangian method to track the particles and calculate their trajectories, and the Eulerian method was used to calculate the flow field. Because of the large velocity and temperature gradient near the wall and the small size of the particle in this question, four forces (e.g., drag force, Saffman lift force, thermophoretic force and Brownian force) acting on the particle are considered. The effects of entering position, Mach number, the size and density of particles are investigated. We discovered that there are three particle movement patterns when they enter the supersonic boundary layer, and that the drag force and Saffman lift force play dominating roles on which pattern will happen in this process. Moreover, the results also reveal that the particle tends to move towards the wall as the diameter and the density of the particle and the Mach number of main flow increases. Finally, we suggested a dimensionless number to describe the three patterns of particle motion. This research provides a better understanding of the particle movement process in the supersonic laminar boundary layer, which can be a useful guidance for the industrial processes involving this phenomenon.

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Quantification of MicroCT Image Intensity and Nanoparticle Concentration in Agarose Gel

ASME 2012 Third International Conference on Micro/Nanoscale Heat and Mass Transfer ◽

10.1115/mnhmt2012-75025 ◽

2012 ◽

Author(s):

A. LeBrun ◽

N. Conn ◽

A. Attaluri ◽

N. Manuchehrabadi ◽

Z. Huang ◽

...

Keyword(s):

Concentration Distribution ◽

Magnetic Nanoparticle ◽

Experimental Studies ◽

Index Number ◽

Nanoparticle Concentration ◽

Nanoparticle Distribution ◽

Tissue Equivalent ◽

Magnetic Nanoparticle Hyperthermia ◽

Scanned Images ◽

Microct Imaging

In recent years, magnetic nanoparticle hyperthermia has attracted a lot of attentions in cancer treatment due to its ability to confine heat within the tumor with minimal collateral thermal damage to the surrounding healthy tissue.1–4 The success of the treatment using magnetic nanoparticles depends on careful planning of the heating duration and achieved temperature elevations. It has been demonstrated by previous research that the generated volumetric heat generation rate or Specific Absorption Rate (SAR) should be proportional to the nanoparticle concentration distribution in the tumors. The difficulty encountered by bioengineers is that the nanoparticle concentration distribution is often unknown, since the tissue is opaque. Recently, high-resolution microCT imaging technique has been used to visualize magnetic nanoparticle distribution in tumors. MicroCT has been shown to generate detailed 3-D density variations induced by nanoparticle depositions in both tissue-equivalent gels and tumor tissues.5–6 However, experimental studies are still needed to quantify the relationship between the microCT pixel index number shown in the scanned images and the actual nanoparticle concentrations.

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