Suppression of particle deposition in tube flow by thermophoresis

Lin, Jyh Shyan; Tsai, Chuen-Tinn; Chang, Cheng-Ping

doi:10.1016/j.jaerosci.2004.05.007

Cited by 31 publications

(12 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…No numerical diffusion is expected to occur since the same computer code was used successfully in our previous studies to solve particle transport equations for convection, diffusion, and thermophoresis (Lin and Tsai 2003;Lin et al 2004Lin et al , 2008. The extrinsic charging efficiency, electrostatic loss, and convection-diffusion loss (L c con−dif ) of charged particles in the charger were then calculated as follows (Marquard et al 2006):…”

Section: Charged Particle Concentration Field and Particle Charging Ementioning

confidence: 99%

Modeling and Validation of Nanoparticle Charging Efficiency of a Single-Wire Corona Unipolar Charger

Chien

Tsai

Chen

et al. 2011

Aerosol Science and Technology

Self Cite

View full text Add to dashboard Cite

A single-wire corona unipolar aerosol charger with a sheath air to avoid particle loss was designed and experimental charging efficiencies were obtained at a fixed aerosol flow rate of 1 L/min using monodisperse silver nanoparticles of 2.5 to 20 nm in diameter. The charger has a cylindrical casing of 30 mm in inner diameter in which a gold wire of 50 µm in diameter and 2 mm in length is used as the discharge electrode. A two-dimensional (2-D) numerical model was developed to predict nanoparticle charging efficiency in the unipolar charger. Laminar flow field was solved by using the Semi-Implicit Method for Pressure Linked Equations (SIMPLER method), while electric potential and ion concentration fields were solved on the basis of Poisson and convection-diffusion equations, respectively. The charged particle concentration fields and charging efficiencies were then calculated on the basis of the convection-diffusion equation in which ion-particle combination coefficient was calculated by Fuchs diffusion charging theory (Fuchs, N. A. (1963). On the Stationary Charge Distribution on Aerosol Particles in a Bipolar Ionic Atmosphere. Geophys. Pura. Appl., 56:185-193). Good agreement between predicted and experimental extrinsic charging efficiencies was obtained. Numerical results showed the advantage of using sheath air to minimize charged particle loss and indicated the location where major charged particle loss occurred. It is expected that the present model can be used to facilitate the design of more efficient corona-wire unipolar charger in the future.

show abstract

Section: Charged Particle Concentration Field and Particle Charging Ementioning

confidence: 99%

Modeling and Validation of Nanoparticle Charging Efficiency of a Single-Wire Corona Unipolar Charger

Chien

Tsai

Chen

et al. 2011

Aerosol Science and Technology

Self Cite

View full text Add to dashboard Cite

show abstract

“…The model, however, overestimated the observed mean orientation. Lin et al 25 performed numerical studies on the orientation distribution of fibers immersed in laminar and turbulent pipe flows. They reported that, in the laminar regime, the fibers were more aligned in the flow direction with increasing Reynolds number.…”

Section: Introductionmentioning

confidence: 99%

Dynamics of prolate ellipsoidal particles in a turbulent channel flow

Mortensen¹,

Andersson²,

Gillissen³

et al. 2008

Physics of Fluids

159

122

View full text Add to dashboard Cite

The dynamical behavior of tiny elongated particles in a directly simulated turbulent flow field is investigated. The ellipsoidal particles are affected both by inertia and hydrodynamic forces and torques. The time evolution of the particle orientation and translational and rotational motions in a statistically steady channel flow is obtained for six different particle classes. The focus is on the influence of particle aspect ratio and the particle response time on the particle dynamics, i.e., distribution, orientation, translation, and rotation. Both ellipsoidal and spherical particles tend to accumulate in the viscous sublayer and preferentially concentrate in regions of low-speed fluid velocity. The translational motion is practically unaffected by the aspect ratio, whereas both mean and fluctuating spin components depend crucially on . The ellipsoids tend to align themselves with the mean flow direction and this tendency becomes more pronounced in the wall proximity when the lateral tilting of the elongated particles is suppressed.

show abstract

“…Thermophoresis is the physical phenomenon in which particles move from higher to lower temperature zone (i.e., in a temperature gradient field) because of the non-zero net molecular momentum transfer on individual particles (Lin and Tsai, 2003;Tsai et al, 2004;Lin et al, 2004). The formula offered in the work of Talbot et al (1980) is popularly used in the literature for the calculation of particle thermophoretic velocity in a temperature gradient field.…”

mentioning

confidence: 99%